| |
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|
|
|
| AASHTO: |
American Association of State Highway
and Transportation Officials. |
| Abrasion
: |
Removal of material
due to a frictional contact. |
| Abrasion
And Scratch Resistance: |
Ability of a material
to resist the infliction of damage in the form of scratches, grooves
and other minor imperfections. |
| ABS: |
Acrylonitrile-Butadiene-Styrene;
a form of thermoplastic. |
| AC: |
Asbestos Cement; a
composite material used in pipe construction. |
| Acceptance: |
By the owner of the
work as being fully complete in accordance with the contract documents. |
| Adapter
Ring: |
In microtunneling,
a fabricated ring, usually made from steel, that serves to mate the
microtunneling machine to the first pipe section. This ring is intended
to create a waterproof seal between the machine and the spigot of
the first joint. |
| Addenda: |
Written or graphic
instruments issued prior to the execution of the agreement, which
modify or interpret the contract documents, drawings and specifications,
by addition, deletions, clarifications or corrections. |
| Additive: |
A substance added in
a small amount, usually to a fluid, for a special purpose such as
to reduce friction, corrosion, etc. |
| Admixture: |
Ingredients added
during mixing; often in construction to aid workability of concrete,
mortar or grout. |
| Advance
: |
The motion of the machine
in a direction toward the face wall of the entrance pit. |
| Advance
rate: |
Speed of advance
of a pipe jack or other trenchless installation through the ground,
generally expressed as either millimetres per minute or metres per
day. |
| Aerial
sewer: |
An unburied sewer (generally
sanitary type), supported on pedestals or bents to provide a suitable
grade line. |
| Aerobic: |
Presence
of unreacted or free oxygen (02). |
| Aggressive
Index (AI): |
Corrosion index established
by the American Water Works Association (AWWA) Standard C-400; established
as a criterion for determining the corrosive tendency of the water
relative to asbestos-cement pipe; calculated from the pH, calcium
hardness (H), and total alkalinity (A) by the formula AI = pH + log
(A * H). |
| Aggressive: |
A property of water
which favors the corrosion of its conveying structure, |
| Agreement: |
The written agreement
between the owner and the contractor covering the work to be performed;
the contract documents are attached to and made a part of the agreements.
Also designated as the contract. |
| Alkalinity: |
The capacity of a
water to neutralize acids; a measure of the buffer capacity of a water.
The major portion of alkalinity in natural waters is caused by (1)
hydroxide, (2) carbonates, and (3) bicarbonates. |
| Alumina: |
An oxide of aluminum
present in clay. |
| AMP: |
Asset Management
Plan; a structured approach for utilities to achieve long term defined
service standards ¡V or ¡V an external bearing used to isolate
the final drive from the thrusting force of the machine. |
| Anaerobic: |
Able to live and grow
where there is no oxygen. |
| Angle
of Repose: |
The angle which the
sloping face of a bank of loose earth, gravel, or other material,
makes with the horizontal. |
| Annular
filler: |
Material for grouting
the annular space between the existing pipeline and the lining system.
|
| Annulus: |
Free space between
the existing pipe and any lining. |
| Anode: |
(opposite of cathode)
The electrode at which oxidation or corrosion occurs. |
| ANSI: |
American National
Standards Institute, Inc. |
| Apparent
Tensile Strength: |
A value of tensile
strength used for comparative purpose that is determined by tensile
testing pipe rings in accordance with ASTM D 2290. This differs from
true tensile strength of the material due to a bending moment induced
by the change in contour of the ring as it is tested. Apparent tensile
strength may be at yield, rupture or both. |
| Apparent
Tensile Yield: |
The apparent tensile
strength calculated for the yield condition. |
| Application
for Payments: |
The form furnished
by the engineer which is to be used by the contractor in requesting
progress payments, and an affidavit of the contractor that progress
payments theretofore received from the owner on account of the work
been applied by the contractor to discharge in full all of the contractor's
obligations stated in prior applications for payment. |
| Approval: |
Accept as satisfactory. |
| Aqueduct: |
Large pipe or conduit
to convey water from distant source. |
| Aqueous: |
Pertaining to water;
an aqueous solution is a water solution. |
| ArcInfo?
: |
GIS program for sewer
data collection and display. |
| Areaway: |
A paved surface,
serving as an entry area basement or subsurface portion of a building,
which is provided with some form of drainage that may be connected
to a sewer line. |
| Arterials: |
Designation of a main
road system with many connecting minor roads. |
| As-Built: |
After a sewer has
been constructed it is checked for conformance to plan specifications.
The actual measurements (As-Built) are written on the plan near the
original plan measurements. The As-Built measurements are often set-off
in a box to differentiate the two measurements. Measurements are of
the elevations for the manhole top cover, manhole invert(s) and ground
level, for percent grade, etc. |
| ASCE: |
American Society of
Civil Engineers. |
| Asset: |
A valuable resource. |
| ASTM: |
American Society of
Testing and Materials, technical organization formed for the development
of standards on characteristics and performance of materials, products,
systems and services, and the promotion of related knowledge. |
| Auger: |
A flighted drive
tube having hex couplings at each end, to transmit torque to the cutting
head and transfer spoil back to the machine. |
| Auger
boring: |
A technique for forming
a bore from a drive pit to a reception pit, by means of a rotating
cutting head. Spoil is removed back to the drive shaft by helically
wound auger flights rotating in a steel casing. The equipment may
have limited steering capability. See guided
auger boring. |
| Auger
boring machine: |
A machine used to
drill earth horizontally by means of a cutting head and auger or other
functionally similar device. The machine may be either cradle
or track type. |
| Auger
MTBM: |
A type of microtunnel
boring machine, which uses auger flights to remove the spoil through
a separate casing placed through the product pipeline. |
| Auger
TBM: |
Tunnel boring machine
in which the excavated soil is removed to the drive shaft by auger
flights passing through the product pipeline pushed in behind the
TBM. |
| Automated
Spoil: |
An automated spoil
transportation system that conveys |
| Available
Water: |
Water necessary for
the performance of work, which may be taken from the fire hydrant
nearest the worksite, given conditions of traffic and terrain which
are compatible with the use of the hydrant for performance of work. |
| AWWA: |
American Water Works
Association. |
|
|
|
| Back reamer: |
A cutting
head attached to the leading end of a drill
string to enlarge the pilot
bore during a pull-back
operation to enable the carrier or sleeve
or casing
to be installed in. |
| Backfall: |
Refers to a length
of pipe having an upward gradient opposite to the direction of flow. |
| Backfill
Density: |
Percent compaction
for pipe backfill (required or expected). |
| Backflow
device: |
Mechanism that prevents
wastewater from flowing back upstream. |
| Backstop: |
Reinforced area of
the entrance pit wall directly behind the track. |
| Band: |
A ring of steel welded
at or near the front of the lead section of casing to cut relief and
strengthen the casing. |
| Baroid: |
Proprietary equipment
to measure the density of annulus grout. |
| Barrel: |
The vertical section
in a manhole between the cone and the benchwall. |
| Base (course): |
A layer of specified
or selected material of planned thickness, constructed on the subgrade
(natural foundation) or subbase for the purpose of distributing load,
providing drainage or upon which a wearing surface or a drainage structure
is placed. |
| Base
: |
The slab structure
which supports a manhole. |
| Base Resin: |
Plastic Materials prior
to compounding with other additives or pigments |
| Base
track: |
See master
track. |
| Batter: |
The slope or inclination
from a vertical plane, as the face or back of a wall. |
| Bedding: |
A prepared layer
of material below a pipeline to ensure uniform support. |
| Benching
or bench: |
The floor of a manhole
into which the channel is set; the bench is raised so that it can
drain to the channel. |
| Benchwall: |
The horizontal bottom
of the manhole normally out of the flow path. |
| Bent sub: |
An offset section of
drill stem close behind the drill head that allows steering corrections
to be made by rotation of the drill
string to orientate the cutting
head. Frequently used in directional
drilling. |
| Bentonite:
|
A colloidal clay
sold under various trade names that forms a slick slurry or gel when
water is added. Also known as drillers mud. See drilling fluid. |
| Berm: |
The space between the
toe of a slope and excavation made for intercepting ditches or borrow
pits. |
| Bid: |
The offer or process
of the bidder submitted on the prescribed form setting forth the prices
for the work to be performed. |
| Bidder: |
Any person, firm, or
corporation submitting a bid for the work. |
| Biological
Corrosion: |
Corrosion that results
from a reaction between the Pipe material and organisms such as bacterial,
algae, and fungi. |
| Bits: |
Replaceable cutting
tools on the cutting head or drill
string. |
| Bitumen: |
A hard or semi-hard
asphaltic residue; often used in construction as a waterproof/barrier
layer. |
| Bituminous
(coating): |
Of or containing bitumen;
as asphalt or tar. |
| Blind
shield: |
Non-mechanical shield
which has a controlled and partly sealed face. |
| BOD: |
Biological Oxygen Demand;
a measure of the need for oxygen by organic processes. |
| Bonds: |
Bid, performance
and payment bonds and other instruments of security furnished by the
contractor and his surety in accordance with the contract documents
and in accordance with the law of the place of the project. |
| Boots:
|
Electrical grade boots
worn by all operators. |
| Bore: |
A generally horizontal
hole produced underground primarily for the purpose of installing
services. |
| Boring
: |
(1) The dislodging
or displacement of spoil by a rotating auger or drill string to produce
a hole called a bore. (2) An earth-drilling process used for installing
conduits or pipelines. (3) Obtaining soil samples for evaluation and
testing. |
| Boring
machine: |
A mechanism to drill
earth. |
| Boring
pit: |
An excavation in the
earth of specified length and width for placing the machine on line
and grade. |
| Box: |
See female
hex connector. |
| Branch
sewer: |
A sewer into which
at least two sanitary, combined or stormwater sewers connect. |
| Breakout: |
Controls the joint
make and/or break mechanism. |
| Bridge
Plank (deck or flooring): |
A corrugated steel
sub-floor on a bridge to support a wearing surface. |
| Brittleness
Temperature: |
Temperature at which
50% of the tested specimens will fail when subjected to an impact
blow. |
| Budgets: |
An amount of money
needed or allocated for a specific use. |
| Building
combined sewers: |
A small diameter
pipe that conveys both wastewater and drainstormwater from a single
property to a combined sewer. |
| Building
sanitary drain: |
A small diameter pipe
that conveys wastewater from a single property (e.g. domestic home)
to a sanitary sewer. |
| Building
Sewer: |
The conduit which
connects building wastewater sources, to the public or street sewer,
including lines serving homes, public buildings, commercial establishments,
and industry structures. In this specification, the building sewer
is referred to in two sections. (1) the section between the building
line and the property line, frequently specified and supervised by
plumbing or housing officials; and (2) the section between the property
line and the street sewer, including the connection thereto frequently
specified and supervised by sewer, public works, or engineering officials
(Referred to also as "house sewer," "building connection,)' "service
connection," or "lateral connection"). |
| Building
stormwater: |
A small diameter pipe
that conveys stormwater runoff drain from the roof and any paved areas
of a single property to a stormwater sewer. |
| Buoyancy: |
The power of supporting
a floating body, including the tendency to float an empty pipe (by
exterior hydraulic pressure). |
| Burst
Strength: |
The internal pressure
required to cause a pipe or fitting to fail within a specified time
period. |
| Bushing: |
See female
hex connector. |
| Butt Fusion: |
A method of joining
polyethylene pipe where two pipe ends and rapidly brought together
under pressure to form a homogeneous bond. |
| Bypass
Pumping: |
The transportation
of sewage which flows around a specific sewer pipe/line section or
sections via any conduit for the purpose of controlling sewage flows
in the specified section or sections without flowing or discharging
onto public or private property. |
| Bypass: |
An arrangement of pipes
and valves whereby the flow may be passed around a hydraulic structure
or appurtenance. Also, a temporary setup to route flow around a part
of a sewer system. |
|
|
|
| Caisson: |
A watertight box
or cylinder used in excavating for foundations or tunnel pits to hold
out water so concreting or other construction can be carried on. |
| Camber: |
Rise or crown of the
center of a bridge, or Bowline through a culvert, above a straight
line through its ends. |
| Can: |
A principal module
which is part of a shield
machine as in microtunneling
or tunnel boring
machines (TBMs). Two or more may be used, depending on the installation
dimensions required and the presence of an articulated joint to facilitate
steering. May also be referred to as a trailing tube. |
| Cantilever: |
The part of a structure
that extends beyond its support. |
| Capital: |
A sum of money used
to implement projects. |
| Carbon
black: |
A black pigment produced
by the incomplete burning of natural gas or oil, that possesses excellent
ultraviolet protective properties. |
| Carriage: |
The mechanical part
of a non-split boring machine that includes the engine or drive motor,
the drive train, thrust block and hydraulic cylinders. |
| Carrier
pipe: |
The tube which carries
the product being transported and which may go through casings at
highway and railroad crossings. It may be made of steel, concrete,
clay, plastic, ductile iron, or other materials. On occasion it may
be bored direct under the highways and railroads. |
| Cased
bore: |
A bore in which a
pipe, usually a steel sleeve, is inserted simultaneously with the
boring operation. Usually associated with auger
boring or pipe
jacking. |
| Casing
: |
A pipe used to line
bore holes through which a pipe(s) called carrier pipes or ducts are
installed. Usually not a Product
Pipe. |
| Casing
adapter: |
A circular mechanism
to provide axial and lateral support of a smaller diameter casing
than that of the casing
pusher. |
| Casing
pipe method: |
Method in which a casing,
generally steel, is pipe jacked into place, within which a product
pipe is inserted later. |
| Casing
pipe: |
A pipe installed
as external protection to a Product Pipe. |
| Casing
pusher: |
The front section of
a boring machine that distributes the thrusting force of the hydraulic
cylinders to the casing and forms the outside of the spoil ejector
system. |
| Cast
iron (CI): |
Sewer pipe material,
sometimes provided as ductile cast iron. |
| Catastrophic
rainfall: |
Rainfall event of return
frequency far in excess of any event collection system design performance
criteria typically, say, a 1 in 200 year storm. |
| Catch
basin: |
A small buried structure
to divert overland stormwater flow into sewer flows. |
| Catchment: |
A geographical area
draining to a sewer or receiving water. |
| Categorization: |
A structured process
of placing items into sets according to related characteristics for
prioritization. |
| Cathode: |
The electrode of an
electrolytic cell at which reduction is the principal reaction (Electrons
flow toward the cathode in the external circuit ). Typical cathodic
processes are cations taking up electron and being discharged, oxygen
being reduced, and the reduction of an element or group of elements
from a higher to a lower valence state. |
| Cathodic
: |
A process by which
the corrosion of a metal pipeline may be protected by the use of an
electrical current. |
| Cathodic
corrosion: |
An unusual condition
(especially with Al, Zn, Pb) in which corrosion is accelerated at
the cathode because the cathodic reaction creates an alkaline condition
which is corrosive to certain metals. |
| Cathodic
protection: |
Preventing corrosion
of a pipeline by using special cathodes (and anodes) to circumvent
corrosive damage by electric current. Also a function of zinc coatings
on iron and steel drainage products - galvanic action. |
| Caulking: |
General term which,
in trenchless technology, refers to methods by which joints may be
closed within a pipeline |
| Cavitation: |
Formulation and sudden
collapse of vapor bubbles in a liquid; usually resulting from local
low pressures - as on the trailing edge of a propeller; this develops
momentary high local pressure which can mechanically destroy a portion
of a surface on which the bubbles collapses. |
| CCTV: |
Closed circuit television
used to carry out internal inspection and survey of pipelines. |
| Cell
: |
Electrochemical system
consisting of an anode and a cathode immersed in an electrolyte. The
anode and cathode may be separate metals or dissimilar areas on the
same metal. The call includes the external circuit which permits the
flow of electrons from the anode toward the cathode. |
| Cell Classification: |
Method of identifying
plastic materials, such as polyethylene, as specified by ASTM D 3350,
where the Cell Classification is based on these six properties: (1)
Density of Base Resin (2) Melt Index (3) Flexural Modulus (4) Tensile
Strength at Yield (5) ESCR (6) Hydrostatic Design Basis and Color |
| Cellar
Drain: |
A pipe or series
of pipe which collect wastewater which leaks, seeps, or flow into
subgrade parts of structures and discharge them into a building sewers
or by other means dispose of such wastewaters into sanitary, combined
or storm sewers (Referred to also as "basement drain"). |
| Centerline: |
The vertical distance
between the center of the drive chuck and the ground plane. |
| CFM: |
Cubic Feet per Minute;
a measure of flow volume. One CFM equals 0.472 liters per second. |
| Change
Order: |
A written order to
the contractor authorizing an addition, deletion or revision in the
work, within the general scope of work of the agreement, authorizing
an adjustment in the agreement price or agreement time. |
| Channel: |
A prepared flow route
within the bench of a manhole that conveys the incoming flow to the
downstream pipe. |
| Chemical
grouting: |
Method for the treatment
of the ground around a shaft or pipeline, using non-cementitious compounds,
in order to facilitate or make possible the installation of an underground
structure. |
| Chemical
resistance: |
Ability to render
service in the transport of a specific chemical for a useful period
of time at a specific concentration and temperature. |
| Chemical
stabilization: |
Renovation method in
which a length of pipeline between two access points is sealed by
the introduction of one or more compounds in solution into the pipe
and surrounding ground and, where appropriate, producing a chemical
reaction. Such systems may perform a variety of functions such as
the sealing of cracks and cavities, the provision of a new wall surface
with improved hydraulic characteristics or ground stabilisation. |
| Chimney: |
The small vertical
section between a manhole frame and cone which is built from brick,
masonry or concrete adjusting rings. |
| Chippers: |
See bits. |
| CIP: |
Cast
Iron Pipe |
| CIPP: |
Cured
In Place Pipe; a rehabilitation technique whereby a flexible resin-impregnated
tube is installed into an existing pipe and then cured to a hard finish,
usually assuming the shape of the existing pipe. |
| Circumferential
Coefficient of Expansion and Contraction: |
The fractional change
in circumference of a material for a unit change in temperature. Expressed
as inches of expansion or contraction per inch of original circumference
per ?/font>F. |
| Circumferential: |
Around the inner surface
of a circular pipe cross section. |
| Cleaning: |
An action of a boring
machine to remove spoil that occurs when the auger is rotating while
axially stationary. |
| Closed
face: |
The ability of a tunnel
boring machine to close or seal the facial opening of the machine
to prevent or slow the entrance of soils into the machine. Also may
be the bulkheading of a hand dug tunnel to slow or stop the inflow
of material. |
| Closed-Circuit
Television Inspection (CCTV): |
Inspection method
utilizing a closed circuit television camera system with appropriate
transport and lighting mechanisms to view the interior surface of
sewer pipes and structures. |
| Close-fit: |
Description of a lining
system in which the new pipe makes close contact with the defective
pipe at normal or minimum diameter. An annulus may occur in sections
where the diameter of the defective pipe is in excess of this. |
| Clutch: |
A mechanical device
that engages or disengages rotary torque from a power source. |
| COD: |
Chemical Oxygen Demand;
a measure of the need for oxygen by chemical processes. |
| Coefficient
: |
A scientifically
based factor that is taken into account during calculations. |
| Coefficient
of Thermal Expansion and Contraction: |
The fractional change
in length of a material for a unit change in temperature. |
| Cofferdam: |
A barrier built in
the water so as to form an enclosure from which the water is pumped
to permit free access to the area within. |
| Cohesionless: |
A material that does
not readily bond with other particles. |
| Cohesive
Soil: |
A soil that when
unconfined has considerable strength when air-dried, and that has
significant cohesion when submerged. |
| Colcrete: |
Proprietary equipment
to measure the workability of annulus grout. |
| Cold
bend: |
To force the Pipe
into a curvature without damage, using no special tools, equipment
or elevated temperatures. |
| Colebrook
White Prandtl: |
A formula for calculating
the flow through pipes. |
| Collapse: |
Critical failure
of a pipeline when its structural fabric disintegrates. |
| Collaring: |
The initial entry of
casing or a cutting head into the earth. |
| Collection
system: |
A network of sewers
which serves one or more catchment areas. |
| Collector
sewer: |
A sewer located in
the public way collects the wastewaters discharged through building
sewers and conducts such flows into larger interceptor sewers and
pumping and treatment works. (Referred to also as "street sewer.") |
| Colloidal: |
Very small insoluble
non diffusible particles that remain in suspension. |
| Combined
sewer sytem: |
A single network of
sewers designed to convey stormwater as well as sanitary flows. |
| Compaction: |
The densification
of a soil by means of mechanical manipulation. |
| Composite
ring brick sewer |
A brick sewer which
consists of a greater number of layers of brick above the springing
line than below the springing line. |
| Compounding: |
The process where
additives and carbon black are homogeneously mixed with the base polyethylene
|
| Compressed
air method: |
General term which,
in trenchless technology, refers to the use of compressed air within
a tunnel or shaft in order to balance ground water and prevent ingress
into an open excavation. |
| Compression
gasket: |
A device which can
be made of several materials in a variety of cross sections and which
serves to secure a tight seal between two pipe sections (e.g., "O"
rings). |
| Compression
ring: |
A ring fitted between
the end bearing area of the bell and spigot to help distribute applied
loads more uniformly. The compression ring is attached to the trailing
end of each pipe and is compressed between the pipe sections during
jacking. The compression rings compensate for slight misalignment,
pipe ends that are not perfectly square, gradual steering corrections,
and other pipe irregularities. Compression rings are also referred
to as spacers. |
| Conductivity: |
A measure of the
ability of a solution to carry an electrical current. conductivity
varies both with the number and type of ions the solution carries. |
| Conduit: |
A broad term that can
include pipe, casing, tunnels, ducts or channels. The term is so broad
that it should not be used as a technical term in boring or tunneling. |
| Cone: |
The section between
the top of a manhole wall and chimney or the frame. The diameter of
the manhole is reduced over the cone section to receive the frame.
The cone section may be concentric or eccentric. |
| Consolidation: |
The gradual reduction
in the volume of a soil mass resulting from an increase in compaction. |
| Continuous
sliplining: |
See sliplining
or lining
with continuous pipe. |
| Contract
documents: |
The Agreement, Addenda,
Instructions to Bidders, Contractor's Bid, the Bonds, the Notice of
Award, the General Conditions, the Supplementary Conditions, Special
Conditions, Technical Conditions, the Specifications, Drawings, Drawing
Modifications, and Notice to Proceed, all make up the Contract Documents. |
| Contract
price: |
The total moneys
payable to the Contractor under the Contract Documents. |
| Contract
time: |
The number of calendar
days stated in the Agreement for the completion of the work. |
| Contracting
officer: |
The owner (guarantee)
- The Individual who is authorized to sign the contract documents
on behalf of the owner's governing body. |
| Contractor: |
The person, firm or
corporation with whom the owner has executed the agreement. |
| Control
Console: |
An electronic unit
inside a container located on the ground surface, that controls the
operation of the microtunneling
machine. The machine operator drives the tunnel from the control console.
Electronic information is transmitted to the control console from
the heading of the machine. This information includes head position,
steering angle, jacking force, progression rates, machine face torque,
slurry and feed line pressures, and laser position. Some control consoles
are equipped with a computer that tracks the data for a real-time
analysis of the tunnel drive. |
| Control
lever: |
A handle that activates
or deactivates a boring
machine function. |
| Conventional
trenching: |
Method in which access
is gained by excavation from ground level to the required level underground
for the installation, maintenance or inspection of a pipe, conduit
or cable. The excavation is then backfilled and the surface reinstated. |
| Conventional
tunnelling: |
Methods of tunnel construction
ranging from manual excavation to the use of self propelled tunnel
boring machines. Where a lining is required bolted segmental rings
are frequently used. |
| Corbel: |
For brick manholes
this term is sometimes used in place of cone, and indicates the gradual
reduction in diameter by indenting brick |
| Core area: |
That part of a sewer
network containing the critical sewers, and other sewers where hydraulic
problems are severe and merit detailed investigation. |
| Corrosion
: |
The destruction of
a material or its properties because of a reaction with its (environment)
surroundings. |
| Corrosion
fatigue: |
Fatigue type cracking
of metal caused by repeated or fluctuating stresses in a corrosive
environment characterized by shorter life than would be encountered
as a result of either the repeated or fluctuating stress alone or
the corrosive environment alone. |
| Corrosion
Index: |
Measurement of the
corrosivity of a water (e.g. Langelier Index, Ryznar Index, Aggressive
Index, etc.) |
| Corrosion
Rate: |
The speed (usually
an average) with which corrosion progresses (it may be linear for
a while); often expressed as though it were linear, in units of mdd
(milligrams per square decimeter per day) for weight change, or mpy
(milligrams per year) for thickness changes. |
| Corrosion
Resistance: |
Ability of a material
to withstand corrosion in a given corrosion system. |
| Corrugated
pipe: |
Pipe with ridges (corrugations)
going around it to make it stiffer and stronger. The corrugations
are usually in the form of a sine wave a+B181nd are usually made of
galvanized steel or aluminum. |
| Cover: |
1) The lid at the
top of the manhole which can be removed when access to the interior
of the manhole is required. |
| Cracks: |
Fracture lines visible
around the circumference and/or along the length of a sewer. |
| Cradle
machine: |
A boring machine
typically carried by another machine that uses winches to advance
the casing. |
| Cradle: |
A structure constructed
from concrete or masonry that provides structural support to a sewer.
It typically surrounds the bottom and sides of a sewer up to the springing
line. |
| Creep: |
The dimensional change,
with time, of a material under continuously applied stress after the
initial elastic deformation. |
| Crew: |
The number of persons
required for the performance of work at a site as determined by the
contractor in response to task difficulty and safety considerations
at the time or location of the work. |
| Critical
sewers: |
Sewers with the most
significant consequences in the event of structural failure. |
| Cross
members: |
The lateral supports
under the track of a boring
machine. |
| Crossing: |
Pipeline installation
in which the primary purpose is to provide one or more passages beneath
a surface obstruction. |
| Crown:
|
(1) Top of pipe segment,
or (2) The highest elevation within a pipe. |
| Crush
lining: |
See Pipe
Eating. |
| CSO: |
Combined Sewer Overflow;
a hydraulic relief point within combined sewer systems designed to
discharge excess flows during wet weather to receiving waters. |
| Cured-in-place
pipe (CIPP): |
A lining system in
which a thin flexible tube of polymer or glass fibre fabric is impregnated
with thermoset resin and expanded by means of fluid pressure into
position on the inner wall of a defective pipeline before curing the
resin to harden the material. The uncured material may be installed
by winch or inverted by water or air pressure, with or without the
aid of a turning belt. |
| Customer: |
Sewer structure owner,
specifically the one requesting the inspection work. |
| Cut
and Cover: |
See Open
Cut. |
| Cutterhead: |
Any rotating tool or
system of tools on a common support that excavates at the face of
a bore. Usually appliesto mechanical methods of excavation. |
| Cutting
bit (cutter head) |
The actual teeth
and supporting structure that is attached to the front of the lead
auger, drill stem or front face of the tunnel boring machine. It is
used to reduce the material that is being drilled or bored to sand
or loose dirt so that it can be conveyed out of the hole. Usually
applies to mechanical methods of excavation, but may also include
fluid jet cutting. |
|
|
|
| Data logger: |
(Also field data logger.)
Keyboard-type device used to electronically record inspection data. |
| Data
reviewers: |
Personnel from other
departments who will review the recorded inspection information for
use in future repair planing or during the auditing process. |
| Dead man: |
A fixed anchor point
used in advancing a saddle or cradle type boring machine. |
| Debris:
|
Accumulation of material
consisting of organic (human waste, food wastes, etc.), (sand, gravel,
wood, etc.), grease or roots. |
| Deck assembly: |
Drive train assembly
for a split design boring machine. |
| Deformed
and reshaped: |
See modified
sliplining. |
| Department
contact: |
Assigned person responsible
to represent the owning department for decision making and necessary
notifications. |
| Dereliction: |
The gradual decay
of a sewer network accelerated by the negligence of effective maintenance. |
| Dewater: |
Any method used to
lower the water table in the vicinity. |
| Diameter
of reamer (d2): |
Largest diameter
of reamer. |
| Diameter
of standard bit (d1): |
Maximum outside diameter
of standard bit. |
| Dimple: |
A term used in tight
fitting pipeline reconstruction, where the new plastic pipe forms
an external departure or a point of expansion slightly beyond the
underlying pipe wall where unsupported at side connections. The dimples
are used for location and reinstatement of lateral sewer service. |
| DIP: |
Ductile Iron Pipe |
| Directional
drilling: |
A steerable system
for the installation of pipes, conduits
and cables in a shallow arc using a surface launched drilling rig.
Traditionally the term applies to large scale crossings in which a
fluid-filled pilot bore is drilled using a fluid-driven motor at the
end of a bend-sub, and is then enlarged by a washover
pipe and back
reamer to the size required for the product
pipe. The required deviation during pilot boring is provided by
the positioning of a bent
sub. Tracking of the drill
string is achieved by the use of a downhole survey tool. |
| Discharge
point: |
The point where the
flows in a sewer are discharged to |
| Discount: |
A reduction in the
calculated price. |
| Discrete
sliplining: |
See sliplining
or lining
with discrete pipes. |
| Diurnal: |
To vary during the
day. |
| Diverting: |
Modifying the normal
wastewater flow to allow access to some specific sewer structure;
often includes bypass pumping. |
| Dog
plate: |
See thrust block. |
| Dogs: |
Moveable protrusions
in the thrust block that engage holes or blocks in the track. |
| Double
ring brick sewer: |
A brick sewer which
consists of two layers of bricks. |
| Drainage
fixture unit: |
A drainage fixture
unit, often referred to as a fixture unit or FU, is a unit of measure
of the waste water flow generated by an appliance, such as a sink
or toilet. For example, the typical full bath has a value of 9 FUs.
See Availability Fee for cost. |
| Drill
bit: |
A tool which cuts
the ground at the head of a Drill
String, usually by mechanical means but may include Fluid
Jet Cutting. |
| Drill
string: |
1) The total length
of drill rods/pipe, bit, swivel joint etc. in a drill bore-hole. 2)
System of rods used with cutting bit or compaction bit attached to
the drive chuck. |
| Drilling
fluid/mud: |
A mixture of water
and usually bentonite and/or polymer continuously pumped to the Cutting
Head to facilitate cutting, reduce required torque, facilitate the
removal of cuttings, stabilize the borehole, cool the head and lubricate
the installation of the Product Pipe. In suitable soil conditions
water alone may be used. |
| Dripper: |
Applied to infiltration
to quantify water dripping into a sewer in a non-continuous way through
a defect or faulty joint. |
| Drive
chuck: |
The female hex connector
located within the casing pusher. |
| Drive
shaft: |
See Jacking
Shaft. |
| Drive/entry
shaft/pit: |
Excavation from which
trenchless technology equipment is launched for the installation of
a pipeline, conduit or cable. It may incorporate a thrust wall to
spread reaction loads to the soil. |
| Drop connection
manhole: |
A manhole in which
the influent pipe enters from above the effluent invert depth. If
the drop occurs in the manhole itself, it is called an "internal"
drop manhole. If the drop occurs a few feet upstream of the manhole,
it is referred to as a "external" drop. |
| Drop
manhole: |
If the upstream pipe
is at a greater elevation than the manhole invert then two inlet connections
to the manhole are made. One is through the wall at the same grade
as the upstream pipe, the other is at the invert so to direct flows
through the channel. The invert connection is made by incorporating
a pipe drop in the upstream pipe. The pipe drop may be outside or
inside the manhole. |
| Dry bore: |
Any drilling or Rod
Pushing system not employing drilling fluid in the process. Usually
associated with guided Impact
Moling, but also some rotary methods. |
| Duct: |
(1) In many instances,
a term interchangeable with pipe. (2) In the boring industry, it is
usually used for small plastic or steel pipes that enclose wires or
cables for electrical or communication usage. (3) Conduit inside which
a utility service is installed. |
| DWF: |
Dry Weather Flow; is
the base flow in a sewer prior to rain induced flows. |
| DWI: |
Dry Weather Inflow;
is the result of flow entering the collection system from connected
sources which are not caused by rainfall. Typically, this could include
water from fire fighting, hydrant abuse, street washing, sump pumps
etc. |
|
|
|
| Earth
piercing: |
(1) Term commonly used
in North America as an alternative to impact
moling. (2) The use of a tool which comprises a percussive hammer
within a suitable casing, generally of torpedo shape. The hammer may
be pneumatic or hydraulic. The term is usually associated with non-steered
devices without rigid attachment to the launch pit, relying upon the
resistance (friction) of the ground for forward movement. During operation
the soil is displaced, not removed. An unsupported bore may be formed
in suitable ground, or a pipe drawn in, or pushed in, behind the tool.
Cables may also be drawn in. |
| Earth
pressure balance (EPB) machine: |
Type of microtunneling
or tunneling machine in which mechanical pressure is applied to the
material at the face and controlled to provide the correct counter-balance
to earth pressures in order to prevent heave or subsidence. The term
is usually not applied to those machines where the pressure originates
from the main Pipe
Jacking rig in the Drive
Shaft/Pit or to systems in which the primary counter-balance of
earth pressures is supplied by pressurized drilling fluid. |
| Earth
pressure balance shield: |
Mechanical tunnelling
shield which utilises a full face to support the ground in front of
the shield and usually employs an auger flight to extract the material
in a controlled manner. |
| Easement
Access: |
Areas within an easement
to which access is required for performance of work. |
| Easement: |
A liberty, privilege,
or advantage without profit which the owner of one parcel of land
may have in the hand of another. In this agreement, all land, other
than public streets, in which the owner has sewer system lines or
installations and right of access to such lines or installations. |
| Effluent: |
A generic term used
to indicate the relative strength of sewer flows; from stormwater
to wastewater to industrial effluent, for example. |
| Efflux: |
Flowing out of. |
| EHMWHD: |
Extra High Molecular
Weight High Density as originally noted in ASTM D1248, Grade P34 materials
were specifically EHMW high-density polyethylene materials. |
| Ejector
pump: |
See Sewage
ejector pump. |
| Elastic
modulus: |
A measure of the
stress buildup associated with a given strain. |
| Electrofusion: |
The joining together
of parts using electrical energy. |
| Elongation: |
The increase in length
of a material stressed in tension. |
| Embankment
(or fill): |
A bank of earth, rock
or other material constructed above the natural ground surface. |
| Embrittlement: |
Loss of ductility
of a material resulting from a chemical or physical change. |
| Emergency
controls: |
Those controls that
stop power to machine or components. |
| Emergency
repair: |
A repair that must
be made while the main is pressurized, or flowing. |
| Emergency
stop: |
A red manually operated
push button that, when activated, stops all functions of the machine. |
| Encrustation: |
Used to describe
deposits left by the partial evaporation of infiltrating groundwater
containing dissolved salts. Can be classified into light, medium or
heavy by percentage loss of cross-sectional area. |
| End Section: |
Flared attachment on
inlet and outlet of a culvert to prevent erosion of the roadbed improve
hydraulic efficiency, and improve appearance. |
| Endurance
Limit: |
The maximum stress
that a material can withstand for an infinitely large number of fatigue
cycles (See Fatigue
Strength). |
| Energy
Gradient: |
Slope of a line joining
the elevations of the energy head of a stream |
| Energy
Head: |
The elevation of
the hydraulic gradient at any section, plus the velocity head. |
| Engineer: |
The person, firm or
corporation named as such in the contract documents; the "Engineer
of Record". |
| Entrance
pit: |
1) An opening in
the earth of specified length and width for placing the machine on
line and grade. 2) See boring
pit. |
| Entry
ring: |
See Launch
Seal. |
| Entry/exit
angle: |
Angle to the ground
surface at which the drill string enters or exits in forming the pilot
bore in a directional
drilling / guided
boring system. |
| Environment: |
The surroundings or
conditions (physical, chemical, mechanical) in which a material exists. |
| Environmental
stress cracking: |
The susceptibility
to crack or craze under the influence of specific chemicals stress
and/or mechanical stress. |
| EPA: |
United States Environmental
Protection Agency |
| EPB: |
Earth
Pressure Balance. |
| Epoxy: |
Resin formed by the
reaction of bisphenol and Epichlorohydrin. |
| Equalizer: |
A culvert placed
where there is no channel but where it is desirable to have standing
water at equal elevations on both sides of a fill. |
| Erosion: |
Deterioration of a
surface by the abrasive action of moving fluids. This is accelerated
by the presence of solid particles or gas bubbles in suspension. When
deterioration is further increased by corrosion, the term "Corrosion-Erosion"
is often used. |
| ERW: |
Electrical Resistance
Welding |
| Estimated
Remaining Life (ERL): |
A value determined
by the inspectors based on experience, judgment, and guidelines within
the manual that predicts the amount of time that a sewer structure
will remain in a "fit-for-use" condition. |
| Estuaries: |
Descriptive of the
transition where rivers meet the sea, and currents meet tides. |
| Execution
department: |
A department that provides
the sewer inspection service. |
| Exfiltration: |
The leakage or discharge
of flows being carried by sewers out into the ground through leaks
in pipes, joints, manholes, or other sewer system structures; the
reverse of "infiltrations." |
| Exit pit: |
An opening located
at the exit of the cutting head or casing. |
| Exit
shaft: |
See Reception
Shaft. |
| Expander: |
A tool which enlarges
a bore during a pull-back
operation by compression of the surrounding ground rather than by
excavation. Sometimes used during a thrust boring process as well
as during directional
drilling / guided
boring pull-back. |
| Extension
track: |
An additional section
of track used in front of the master track. |
|
|
|
| Fabric: |
Used to describe the
physical material from which a pipe is made: vitrified clay; brick;
concrete, for example. |
| Face
stability: |
Stability of the
excavated face of a tunnel or pipe jack. |
| Face: |
Wall of the entrance
pit into which the bore is made. |
| Fairings: |
Molding features
at the ends at the ends of pipes, usually of varying dimensions to
the main pipe, to facilitate easy jointing. |
| Fatigue
Strength: |
The stress to which
a material can be subjected for a specified number of fatigue cycles. |
| Fatigue: |
The phenomenon leading
to fracture under repeated or fluctuating stresses having a maximum
value less than the tensile strength of the material. |
| Feet per
second: |
US customary unit for
velocity. One foot per second equals 304.8 millimeters per second;
or 0.3048 meters per second. (abbrev. ft/s). |
| Feet: |
US customary unit
for measuring length. One foot equals 304.8 mm; or 0.3048 meters.
(abbrev. ft). |
| Female
hex connector: |
A hexagonal shaped
socket. |
| Ferro-cement: |
A rehabilitation
technique that employs steel fabric mesh, usually in multiple layers
but with the maximum mesh diameter not exceeding 2 mm (1/8 inch),
which is fixed to the existing sewer and then covered in high strength
grout, either placed in situ by man
entry work to form a structural lining or pre-formed into segments
for later installation. |
| Field
data logger: |
See data
logger. |
| Field
Orders: |
A written order issued
by the engineer clarifies or interprets the contract documents in
accordance with the terms of the contract or orders minor changes
in the work in accordance with the terms of the contract. |
| Filter: |
Granular material placed
around a submarine pipe to facilitate drainage and at the same time
strain or prevent the admission of silt or sediment. |
| Final
drive: |
The final reduction
unit in the drive line. |
| Fit-for-use
criteria: |
Criteria used to determine
if sewer structures are in a condition that justifies continued operation
for its designated service. |
| Fixture
Unit: |
See Drainage
fixture unit |
| Flare
or flaring: |
The bending out of
the front end of the lead joint to give clearance. Depending on ground
conditions, the flares may have all cracks, or cuts fully welded,
or a complete flare not welded, or a segmented flare where only portions
of the joint are flared. |
| Flash
Point: |
Temperature at which
a material begins to vaporize. |
| Flexible: |
Readily bent or deformed
without permanent damage. |
| Flexural
Modulus: |
The slope of the
curve defined by flexural load versus resultant strain. A high flexural
modulus indicates a stiffer material. |
| Flexural
Strength: |
The strength of a material
in bending expressed as the tensile stress of the outermost fibers
at the instant of failure. |
| Flight: |
The spiral plates
surrounding the tube of an auger. |
| Flow :
|
(1) Turns drilling
fluid flow on. (2) Turns air on. |
| Flow
attenuation: |
The process of reducing
the peak flow rate in a collection system or of redistributing a proportion
of the flow already in a collection system. |
| Flow control: |
A method whereby normal
sewer flows or a portion of normal sewer flows are blocked, retarded,
or diverted (bypassed) within certain areas of the sewer collection
system. |
| Flow
reduction: |
The process of decreasing
flows into a collection system or of removing a proportion of the
flow already in a collection system. |
| Flow simulation: |
The replicating of
flows in surface water or combined collection systems using a dynamic
digital model. |
| Flow
split: |
Location where wastewater
exits a manhole through more than one pipe. Also refers to a high
point in the sewer system that causes wastewater to flow away from
the manhole in more than one direction. |
| Fluid
jet cut: |
See jet
cutting. |
| Fluid-assisted
boring/drilling |
A type of guided
boring technique using a combination of mechanical drilling and
pressurized fluid jets to provide the soil cutting action. |
| Fluorescein
dye |
A potent Kelly-green
fluorescent water dye used to "color" waste streams and identify their
flow paths (flow path verification). |
| Fold
& form lining: |
Method of pipeline
rehabilitation in which a liner is folded to reduce its size before
insertion and reversion to its original shape by the application of
pressure and/or heat. See also Lining
with Close-Fit Pipes. |
| Fold and
Form Pipe: |
A pipe rehabilitation
method where a plastic pipe manufactured in a folded shape of reduced
cross-sectional area is pulled into an existing conduit and subsequently
expanded will. pressure and heat. The reformed plastic pipe fits snugly
to and takes the shape of the ID of the host pipe. |
| Force
main: |
A pipeline that conveys
sanitary, combined or stormwater flow under pressure from a pumping
(or lift) station to a discharge point. |
| Forward
rotation: |
The clockwise rotation
of the auger as viewed from the machine end. |
| Fouling: |
An accumulation of
deposits. This term includes accumulation and growth of marine organisms
on a submerged metal surface and also includes the accumulation of
deposits (usually inorganic) on heat exchanger tubing, |
| Foundation
drain: |
A pipe or series of
pipes which collect groundwater from the foundation or footing of
structures and discharge it into sanitary, storm, or combined sewers,
or to other points of disposal for the purpose of draining unwanted
waters away from such structures. |
| Fracture
mechanics: |
A quantitative analysis
for evaluating structural reliability in terms of applied stress,
crack length, and specimen geometry. |
| Fractures: |
Cracks visibly open
along the length and/or circumference of the conduit with the pieces
still in place. |
| Frame
ring: |
In a manhole, it
is the metal frame which supports the cover. |
| Frame:
|
A cast iron unit at
the ground surface that provides entry into the manhole. |
| Free
boring: |
To bore or drill
without the use of casing
installed at the same time as the hole is cut. Not recommended for
use with augers. |
| Front
drive: |
See drive
chuck. |
|
|
|
| Gallons
per minute: |
US customary unit
to measure liquid volume discharge rate. One gallon per minute equals
0.063 liters per second. (abbrev. GPM). |
| Galvanic
cell: |
A cell consisting of
two dissimilar metals in contact with each other and with a common
electrolyte (sometimes refers to two similar metals in contact with
each other but with dissimilar electrolytes; differences can be small
and more specifically defined as a concentration cell). |
| Galvanizing
(spelter coating): |
A plating for iron
and steel composing primarily of zinc. It may be applied electronically
or by dipping the pipe or casing in molten zinc (the fumes are poisonous
to breathe). |
| General
corrosion: |
Corrosion in a uniform
manner. |
| Geographical
Information System (GIS): |
A computer software
system designed to store,manipulate, analyze, and print geographically
referenced information. |
| Gloves: |
Gloves (cloth, rubber
& leather) used by operators, crew members and tracking locator operators
that provide maximum protection against electrical shock if properly
used. |
| Gradation: |
Sieve analysis of
aggregates. |
| Grade: |
The elevations shown
on plans and/or survey grade stakes for the installation of the carrier
pipe. It is occasionally to give elevations for casing. In most cases,
it is given to the flow line but can also be given to the top of the
pipe or casing.
|
| Gradient: |
See Grade. |
| Grain: |
A portion of a solid
metal (usually a fraction of an inch in size) in which the atoms are
arranged in an orderly pattern. The irregular junction of two adjacent
grains is known as a grain boundary; also a unit of weight, 1/7000th
of a pound; also used in connection with soil particles i.e. = grain
of sand. |
| Granular: |
Technical term referring
to (the uniform size on grains of crystals in rock. |
| Graphitization
(graphitic corrosion): |
Corrosion of gray cast
iron in which the metallic constituents are converted to corrosion
products, leaving the graphite flakes intact, Graphitization is also
used in a metallurgical sense to mean the decomposition of iron carbide
to form iron and graphite. |
| Gravity
sewer: |
A sewer that is designed
to operate under open channel conditions (below pipe full capacity)
up to a maximum design flow at which point it will become surcharged. |
| GRC: |
Glass fiber Reinforced
Concrete; a rehabilitation lining. |
| Grease
trap: |
Mechanism in a lateral
that collects grease before it can reach a main line. |
| Grinder
pump: |
See Sewage
grinder pump. |
| Grip: |
Applies travel to
rod or pipe. |
| Ground
mat cables: |
Cables connecting the
drill rack to the ground mats. |
| Ground
mat: |
Metal mats rolled
out on either side of drill rack for operators and crew to stand on
during operation to give grounding protection in case of electrical
strike. |
| Ground
plane: |
The surface upon which
the machine is placed. |
| Ground
rod : |
This is a copper/brass
rod which is hand driven into the ground and is connected to the drill
rack and mats to provide adequate grounding of unit and personnel. |
| Ground
rod cable: |
Cable connecting the
mats and drill rig to the ground rod. |
| Ground
water table (or level): |
Upper surface of
the zone of saturation in permeable rock or soil (when the upper surface
is confined by impermeable rock, the water table is absent). |
| Groundwater
table: |
See reference groundwater
level. |
| Grout: |
(1) Material used
to seal pipeline and manhole cracks; also used to seal connections
within sewer structures. (2) A material, usually cement based, used
to fill the annulus between the existing pipe and the lining; and
also to fill voids outside the existing pipeline. (3) A material such
as a cement slurry, sand or pea gravel that is pumped into voids. |
| Grouting: |
(1) Filling of the
annular space between the Host
pipe and the Carrier
Pipe. Grouting is also used to fill the space around laterals
and between the new pipe and manholes. Other uses of grouting are
for localized repairs of defective pipes and ground improvement prior
to excavation during new installations. (2) The process of filling
voids or modifying/improving ground conditions. Grouting materials
may be cementitous, chemical, or other mixtures. In microtunneling,
grouting may be used for filling voids around the pipe or shaft, or
for improving ground conditions. (3) A method of filling voids with
cementitous grout. |
| GRP: |
Glass Reinforced
Plastic, a family of rehabilitation linings. Often generically known
as Reinforced Plastic Mortar (RPM) and Reinforced Thermosetting Resin
(RTR). |
| Guard: |
A protective device
fitted to the machine to minimize the possibility of inadvertent contact
with hazards. |
| Guidance
system: |
The guidance system
continuously confirms the position of the MTBM.
|
| Guide
rail: |
Device used to support
or guide, first the shield and then the pipe within the drive shaft
during a pipe jacking operation. |
| Guided
auger boring: |
A term applied to
auger boring systems which are similar to microtunneling, but with
the guidance mechanism actuator sited in the drive Shaft (e.g. a hydraulic
wrench which turns a steel casing with an asymmetric face at the cutting
head). The term may also be applied to those auger boring systems
with rudimentary articulation of the casing near the head activated
by rods from the drive pit. |
| Guided
boring: |
Method for the installation
of pipes, conduits
and cables using a surface-launched drilling rig. A pilot
bore is drilled using a rotating drill
string and is then enlarged by a back
reamer to the size required for the product
pipe. The necessary deviation during the pilot boring is provided
by a slanted face to the drill head, an asymmetric drill head, eccentric
fluid jets or a combination of these, usually in conjunction with
a locator. |
| Guided
drilling: |
See Guided
Boring. |
| Gunite: |
A rehabilitation technique
that employs steel reinforcement fixed to the existing sewer which
is covered in concrete, usually spray applied. |
| Gusher: |
Applied to infiltration
to quantify water flowing under pressure into a sewer in a continuous
way through a defect or faulty joint. |
| GWI: |
Groundwater Infiltration;
results from the movement of groundwater in the saturated zone into
the collection system through defects in the components of the system
located below the water table. |
|
|
|
| Hand
excavation: |
The technique used
to remove the material (rock, dirt, sand, etc.) by hand held tools
(pick, shovel, etc.) from the tunnel face or open ditch. |
| HDPE: |
High Density Polyethylene,
see polyethylene. |
| Head
(Static): |
The height of water
above any plane or point of references (The energy possessed by each
unit of weight of a liquid, expressed as the vertical height through
which a unit of weight would have to fall to release the average energy
posed.) Standard unit of measure shall be the foot. Head in feet for
water at 68?/font> F is 1 psi = 2.310 ft. |
| Headwall: |
A wall (of any material)
at the end of a culvert or, drain to serve one or more of the following
purposes: protect fill from scour or undermining; increase hydraulic
efficiency, divert direction of flow, and serve as a retaining wall. |
| Heaving: |
Process in which
the ground in front of a pipe jack may be displaced forward and upward
causing a lifting of the ground surface. |
| Height
of Cover (HC): |
Distance from crown
of a culvert or conduit to the finished road surface, or ground surface,
or the base of the rail. |
| Helicoid: |
A section of auger
flight. |
| Hex drive: |
See drive
chuck. |
| High
Density Polyethylene: |
A plastic resin made
by the copolymerization of ethylene and a small amount of another
hydrocarbon. The resulting base resin density, before additives or
pigments, is greater than 0.941 gins/cc. |
| Highway
drain: |
A pipe that conveys
stormwater runoff from a catchment area street catchbasin to a discharge
point. |
| Hold
down: |
A hinged or removable
assembly that secures the boring machine to the track. |
| Holiday: |
Any discontinuity or
bare spot in a coated surface. |
| Hook
rollers: |
See hold
down. |
| Hoop Stress: |
The circumferential
force per unit areas, psi, in the pipe wall due to internal pressure. |
| Horizontal
directional drilling (HDD): |
See directional
drilling. |
| Horizontal
earth boring machine: |
A machine used to bore
horizontally through the earth by means of a rotating tool, or nonrotating
pushing or piercing tool. |
| Horizontal
earth boring: |
(Auger Boring, Boring
& Jacking) The use of auger
boring machines to prepare holes by the installation of a casing
whereby the spoil is removed by the use of augers. |
| Horizontal
rotary drilling: |
The mechanical installation
of pipe or casing by rotating methods which do not use augers for
the removal of spoil. Usually uses a fluid of water and bentonite
to remove spoil. |
| Host
pipe: |
The tube which carries
the product being transported and which may go through casings at
highway and railroad crossings. It may be made of steel, concrete,
clay, plastic, ductile iron, or other materials. On occasion it may
be bored direct under the highways and railroads. |
| Hydraulic
Cleaning: |
Techniques and methods
used to clean sewer lines with water e.g.: water pumped in the form
of a high velocity spray and water flowing by gravity or head pressure.
Devices include high velocity jet cleaners, cleaning balls, and hinged
disc cleaners. |
| Hydraulic
Grade Line (HGL): |
See Hydraulic
gradient. |
| Hydraulic
gradient: |
An imaginary line through
the points to which water would rise in a series of vertical tubes
connected to the pipe. In an open channel, the water surface itself
is the hydraulic grade line. |
| Hydraulic
radius: |
The area of the water
prism in the pipe or channel divided by the wetted perimeter. Thus,
for a round conduit flowing full or half full, the hydraulic radius
is d/4, Another term sometimes used for this quantity is hydraulic
mean depth. |
| Hydraulic
reinforcement: |
The provision of an
additional sewer which in conjunction with an existing sewer increases
overall flow capacity. |
| Hydraulics: |
That branch of science
or engineering which treats water or other fluid in motions. |
| Hydrocarbons,
Gaseous: |
An organic compound
made up of the elements of carbon and hydrogen that exists as a gas
at ambient conditions (14.7 psi, 73.4?/font> F). |
| Hydrocarbons,
Liquid: |
An organic compound
made up of the elements of carbon and hydrogen that exists as a liquid
at ambient conditions (14.7 psi, 73.4?/font> F). |
| Hydrocleaning: |
Use of high pressure,
high velocity water for cleaning; specifically as applied to passing
hydrocleaning nozzles through sewer pipelines to clean walls and flush
debris. |
| Hydrogen
blistering: |
Subsurface voids
produced in a metal by hydrogen absorption in (usually) low strength
alloys with resulting surface bulges. |
| Hydrogen
Induced Cracking (HIC): |
A form of hydrogen
blistering in which stepwise internal cracks are created that can
affect the integrity of the metal. |
| Hydrogen
ion (pH): |
Refers to acidity
or alkalinity of water or soil. An ion is a charged atom or group
of atoms in solution or in a gas. Solutions contain equivalent numbers
of positive and negative ions. |
| Hydrogen
Stress Cracking: |
A cracking process
that results from the presence of hydrogen in a metal in combination
with tensile stress. It occurs most frequently with high strength
alloys. |
| Hydrogen
Sulfide: |
An odorous gas sometimes
found in sewer systems. Recognizable by a rotten egg odor. Chemical
formula is H2S. |
| Hydrostatic
Design Basis: |
Hydrostatic design
basis can be defined as the normalized long-term strength or calculated
hoop strength of the material at 100,000 hours obtained by long-term
hydrostatic testing of pipe samples from which the probable safe life
of the pipe at various stress levels (working pressures) and at various
temperatures can be predicted. |
|
|
|
| I/I: |
Infiltration/Inflow;
this is the sum of all the extraneous contributions to the collection
system. |
| ICG: |
Internal Condition
Grade; numeric criteria applied to visual images of sewers to develop
a priority rating based on defects observed. |
| IGN: |
Information Guidance
Notes; an international reference source for some lining materials. |
| Ignition
temperature: |
Temperature at which
the vapors emitted from a material will ignite either without exposure
to a flame (self-ignition) or when a flame is introduced (flash ignition). |
| Impact
: |
Stress in a structure
caused by the force of a vibratory, dropping,, or moving loads. This
is generally a percentage of the live load. |
| Impact
machines: |
A type of machine that
pierces the earth (piercing tool) or rams an object to produce a bore
(ramming machine). |
| Impact
moling: |
Method of creating
a bore using a pneumatic or hydaulic hammer within a casing, generally
of torpedo shape. The term is usually associated with non-steered
or limited steering devices without rigid attachment to the launch
pit, relying upon the resistance of the ground for forward movement.
During the operation the soil is displaced, not removed. An unsupported
bore may be formed in suitable ground, or a pipe drawn in, or pushed
in, behind the impact moling tool. Cables may also be drawn in. |
| Impact
ramming: |
See pipe
ramming. |
| Impact
strength: |
The ability of a
material to withstand shock loading. |
| Impervious: |
Impenetrable. Completely
resisting entrance of liquids. |
| In line/on
line replacement: |
The breaking out
of an existing pipeline and the installation of a new service on the
same line. See replacement. |
| In situ: |
Describes work on site;
in the original place. For example, in situ concrete would differentiate
cast in place concrete from precast concrete. |
| Inadvertent
contact: |
Contact between a
person and a hazard resulting from the person¡¦s unplanned actions
during normal operation or servicing of the machine. |
| Inert
material: |
A material which is
not very reactive, such as a noble metal or plastic. |
| Infiltration/Inflow
(II): |
The total quantity
of water from both infiltration and inflow without distinguishing
the source. |
| Infiltration: |
(1) Penetration of
freshwater or groundwater into the sewer system through cracks, defective
joints in the pipeline, and holes, or through lateral connections,
manholes or inspection chambers. (2) All extraneous waters (storm
water and ground water) which enter the wastewater collection system
through various sources including, among others, pipe defects, defective
service connections, manhole covers, roof leaders, and foundation
drains. |
| Inflow: |
Water discharged
into a sewer system and service connections from sources on the surface. |
| Inhibitor: |
(1) A chemical substance
or combination of substances which, when present in the environment,
prevents or reduces corrosion without significant reaction with the
components of the environment. (2) A substance which sharply reduces
corrosion, when added to water, acid, or other liquid in small amounts;
also, a chemical additive that delays the chemical reaction in epoxy
resin systems. |
| Input
parameter for electrical drive: |
Maximum continuous
rated voltage and amperage. |
| Input
parameter for hydraulic or pneumatic drive: |
Maximum continuous
rated torque and shaft speed. |
| Input
parameter for mechanical drive: |
Maximum continuous
rated torque and shaft speed. |
| Insertion: |
See sliplining. |
| Inspection
event number: |
The unique reference
number used to identify a specific inspection of a sewer structure
or a group of sewer structures, referred to as an Inspection. |
| Inspector: |
The owner's on-site
representative responsible for inspection and acceptance, approval,
or rejection of work performed as set forth in these specifications. |
| Interaction: |
The division of load
carrying between pipe and backfill and the relationship of one to
the other. |
| Intercepting
drain: |
A ditch or trench filled
with a pervious filter material around a subdrainage pipe. |
| Interceptor
sewer: |
A sewer that conveys
flow from a trunk sanitary sewer or dry weather flow plus a small
volume of stormwater from a trunk combined sewer to a wastewater treatment
plant. |
| Intergranular
Stress Corrosion Cracking (IGSCC): |
Stress corrosion cracking
in which the cracking occurs along grain boundaries. |
| Interjack
pipes: |
Pipes specially designed
for use with an Intermediate
Jacking Station. |
| Interjack
station: |
See Intermediate
Jacking Station. |
| Intermediate
jacking method: |
Pipe
jacking method to redistribute the jacking force by the use of
intermediate jacking stations. |
| Intermediate
Jacking Station: |
A fabricated steel
cylinder fitted with hydraulic jacks that is incorporated into a pipeline
between two pipe segments. Its function is to distribute the jacking
load over the pipe string on long drives. |
| Internal
corrosion: |
Corrosion that occurs
inside a pipe because of the physical, chemical, or biological interactions
between the pipe and the water as opposed to forces acting outside
the pipe, such as soil, weather, or stress conditions. |
| Internal
erosion: |
Abrasion and corrosion
on the inside diameter of the pipe or tubing due to the fluid that
is being transported. |
| Internal
inspection: |
Means of ascertaining
the condition of pipelines, either by visual inspection for man-entry
size or by the use of remote control instrumentation. |
| Internal
pipe inspection: |
The television inspection
of a sewer line section. A CC-TV camera is moved through the line
at a slow rate and a continuous picture is transmitted to an above
ground monitor (see also PHYSICAL PIPE INSPECTION). |
| Inversion: |
The process of turning
a fabric tube inside out with water or air pressure as is done at
installation of a cured in place pipe. |
| Invert
: |
(1) The lowest point
on the pipe circumference; also the defined channel in the manhole
platform that directs flow from inlet pipe to outlet pipe. (2) The
inside bottom, lowest elevation, of a sewer pipe. |
| Invert
level (elevation): |
The level (elevation)
of the lowest portion of a liquid-carrying conduit, such as a sewer,
which determines the hydraulic gradient available for moving the contained
liquid. |
| Ion: |
An electrically charged
atom (Na+, Al+3, CL-, S-2) or group of atoms known as "radicals" (NH4+,
SO4-2, PO4 3). |
| Ionization: |
Dissociation of ions
in anaqueous solution (e.g., H2C03 - H+ + HCO3- or H2O - H+ OH). |
|
|
|
| Jacking
force: |
Force applied to pipes
in a pipe
jacking operation. |
| Jacking
frame: |
A structural component
that houses the hydraulic cylinders used to propel the microtunneling
machine and pipeline. The jacking frame serves to distribute the thrust
load to the pipeline and the reaction load to the shaft wall or thrust
wall. |
| Jacking
pipes: |
Pipes designed to be
installed using pipe
jacking techniques. |
| Jacking
pit: |
The excavation that
the machinery is set into to install a casing
or tunnel. (in years past, it has also been known as a Glory Hole) |
| Jacking
shaft: |
Excavation from which
trenchless technology equipment is launched for the installation or
renovation of a pipeline, conduit or cable. May incorporate a thrust
wall to spread reaction loads to the ground. |
| Jacking
shield: |
A fabricated steel
cylinder from within which the excavation is carried out either by
hand or machine. Incorporated within the shield are facilities to
allow it to be adjusted to control line and grade. |
| Jacking
station (IJS): |
See Immediate
Jacking station. |
| Jacking: |
The actual pushing
of pipe or casing in an excavated hole. This is usually done with
hydraulic cylinders (jacks), but has been done with mechanical jacks,
air jacks and just about anything else that man could imagine. |
| Jet cutting
(jetting): |
(1) A type of Directional
Drilling or Guided
Boring technique using pressurized fluid jets to provide the soil
cutting action. (2) A process using high pressure water to wash out
the face of a utility crossing without any mechanical or hand excavation
of the soils in the face. This process has also been used to remove
the material in open pit mining. |
| Joint
sealing: |
Method in which an
inflatable packer is inserted into a pipeline to span a leaking joint,
resin or grout being injected until the joint is sealed and the packer
then removed. |
| Joints: |
The means of connecting
sectional lengths of sewer pipe into a continuous sewer line using
various types of jointing materials. The number of joints depends
on the lengths of the pipe sections used in the specific sewer construction
work. |
|
|
|
| Keepers: |
See hold
down. |
| Kip: |
A stress unit equal
to 1000 pounds. |
|
|
|
| Lateral
: |
A service line that
transports wastewater from individual buildings to a main sewer line. |
| Lateral
connection: |
The point at which
the downstream end of a building drain or sewer connects into a larger
diameter sewer. |
| Lateral
spur: |
The lateral spur
is that section of the sewer lateral which extends from the County
sewer line to the end of the sewer lateral from the house/building
which generally terminates one foot within the property line. Lateral
spurs are installed at the time the sewer is constructed to prevent
future dig-up of the street. |
| Launch
pit: |
Also known as Drive
Pit, but more usually associated with "launching" an Impact
Moling tool. |
| Launch
seal: |
A mechanical seal,
usually comprised of a rubber flange that is mounted to the wall of
the drive shaft. The flange seal is distended by the MTBM as it passes
through creating a seal to prevent water or lubrication inflow into
the shaft during tunneling operations. |
| lb/ft: |
US customary units
for weight per unit length. One lb/ft equals 1.488 kilograms per meter. |
| Lead
pipe: |
The leading pipe
designed to fit the rear of a jacking
shield and over which the trailing end of the shield is fitted. |
| Length
of drill rod: |
Nominal length of drill
rod. |
| Line: |
(1) The specified
direction of the proposed bore in a horizontal plane. (2) (Path) The
shortest distance between two points as laid out by a survey crew
for the installation of pipelines and their bores and tunnels. |
| Liner
plate: |
A proprietary product,
used to line tunnels instead of casing, and comes in formed steel
segments. When these segments are bolted together they form a structural
tube to protect the tunnel from collapsing. The segments are made
so that they may be bolted together from inside the tunnel. |
| Lining
with close-fit pipes: |
Method of lining
with a continuous pipe for which the cross section is reduced to facilitate
installation, and reverted after installation to provide a close fit
to the existing pipe. |
| Lining
with continuous pipe: |
Method of lining with
a pipe made continuous for the length of the section to be renovated
prior to insertion, and which has not been shaped to give a cross
sectional diameter smaller than its final diameter after installation. |
| Lining
with cured-in-place pipes: |
Method of lining
with a flexible tube impregnated with a thermosetting resin, which
produces a pipe after resin cure. |
| Lining
with discrete pipes: |
Method of lining with
pipes shorter than the section to be renovated which are not jointed
prior to insertion to form a continuous pipe, and which have not been
shaped to give them a cross sectional diameter smaller than their
final diameter after installation. |
| Lining
with inserted hose: |
Method of lining
with a loose fit reinforced hose to provide a pipe lining such that
fluids may be conveyed under pressure. |
| Lining
with pipe segments: |
Method of lining with
pipe sections made of at least two pieces with both longitudinal and
circumferential joints. |
| Lining
with spirally wound pipes: |
Method of lining
with a profiled strip, spirallywound to form a continuous pipe after
installation. |
| Lining: |
A rehabilitation process
where a length of material is introduced to extend the life of the
existing sewer. The lining may or may not utilize some structural
strength from the existing sewer; and it may or may not function as
a structural enhancement within the existing sewer. or An internal,
non-structural coating or lining material applied to a pipe. |
| Lipping: |
A degree of overlap
between adjacent units. |
| Live insertion: |
Installation of a liner
whilst the product
pipe remains in service. |
| Localized
(spot) repair:
|
Repair work on a
pipe, particularly sewerage, to an extent less than the run between
two access points. |
| Locator: |
An electronic instrument
used to determine the position and strength of electro-magnetic signals
emitted from a transmitter sonde in the pilot head of a boring system,
in an impact
moling tool or from existing underground services which have been
energised. Sometimes referred to as a Walkover
System. |
| Long
term strength: |
The hoop stress in
the wall of the pipe is sufficiently low that creep (relaxation) of
the materials is nil and assures service life in excess of 50 years. |
| Low load
method: |
A pipe jacking method
in which separate provision is made to carry the jacking load, the
pipe being installed carrying little or none of the jacking force. |
| Lubrication: |
A fluid, normally
bentonite, used to reduce jacking loads on the jacking pipe. |
|
|
|
| Machine
roller: |
See cam
follower. |
| Major
blockage: |
A blockage (structural
defect, collapse, protruding service connection, debris) which prohibits
manhole-to-manhole cleaning, TV inspections pipe flow, or rehabilitation
procedures. |
| Male hex
connector: |
See shank. |
| Man-accessible: |
Description of a
pipe or excavation which can be physically entered by an operative. |
| Man-entry: |
Describes any trenchless
technology process which requires an operative to enter a pipe, duct
or bore. OSHA has no minimum size limit for Man-Entry; however, they
address a much broader concept of "confined space" in Title 29 Code
of Federal Regulations Part 1910.146. The minimum size for which this
is permissible in the UK is 900 mm (approximately 36 in.). |
| Manhole: |
A structure that
allows access to the sewer system. |
| Manning's
Formula: |
An equation for the
value of coefficient c in the Chezy Formula, the factors of which
are the hydraulic radius and a coefficient of roughness; an equation
itself used to calculate flows in gravity channels and conduits. |
| Manual
Inspection: |
Method of sewer inspection
that usually involves physical entry and hands-on examination; also
includes used of CCTV camera with manual puppetting (e.g., in manholes). |
| Manual
mechanical shield: |
Open shield in which
manpower is used to excavate the material but which has some steering
capability. |
| Marsh
funnel viscosity: |
An instrument used
to measure viscosity. For trenchless applications, used to determine
slurry viscosity. |
| Master
casing pusher: |
See casing
pusher. |
| Master
track: |
The rear most track
section. |
| Maximum
allowable operating pressure: |
The highest working
pressure expected and designed for during the service-life of the
main. |
| Measurement
while drilling (MWD): |
Borehole survey instrumentation
that provides continuous information simultaneously with drilling
operations, usually transmitting to a display at or near the drilling
rig. |
| Mechanical
cleaning: |
Methods used to clean
sewer lines of debris mechanically with devices such as rodding machines,
bucket machines winch-pulled brushes, etc. |
| Mechanical
props repair: |
See Rerounding. |
| Median
barrier: |
A double-faced guardrail
in the median or island dividing two adjacent roadways. |
| Melt
flow rate: |
The quantity of thermoplastic
material in grams that flows through an orifice during a 10-minute
time span under conditions as specified by ASTM D 1238. |
| Melt flow: |
A measure of the molten
material's fluidity. |
| Melt
index: |
The melt flow of
a thermoplastic material as determined under Condition E of ASTM D
1238. Condition C or high load melt index produces a higher melt flow
for a given material as a result of the greater force applied to the
sample during the test. |
| Melt viscosity: |
The resistance of the
molten material to flow. |
| microtunnel
boring machine (MTBM): |
The microtunnel boring
machine (MTBM) refers to the microtunnel shield jacked through the
earth which excavates the ground in advance of the pipe being installed. |
| Microtunneling: |
A trenchless construction
method for installing pipelines. Microtunneling uses all of the following
features are utilized during construction: (1) Remote controlled -
The microtunneling boring machine (MTBM) is operated from a control
panel, normally located on the surface. The system simultaneously
installs pipe as spoil is excavated and removed. Personnel entry is
not required for routine operation. (2) Guided - The guidance system
usually references a laser beam projected onto a target in the MTBM,
capable of installing gravity sewers or other types of pipelines to
the required tolerance, for line and grade. (3) Pipe jacked - The
process of constructing a pipeline by consecutively pushing pipes
and MTBM through the ground using a jacking system for thrust. (4)
Continuously supported ¡V Continuous pressure is provided to the
face of the excavation to balance groundwater and earth pressures. |
| Midi-rig: |
Steerable surface-launched
equipment for the installation of pipes, conduits and cables. Applied
to intermediate sized drilling rigs used as either a small directional
drilling machine or a large guided
boring machine. Tracking of the drill string may be achieved be
either a downhole survey
tool or a locator. |
| Million
gallons per day (mgd): |
US customary unit for
flow measurement. One MGD equals 43.81 liters per second. |
| Mini-horizontal
directional drilling (Mini-HDD): |
A term sometimes
applied to Guided
Boring. |
| Mixed
face: |
A soil condition that
presents two or more different types of material in the path of the
bore. |
| Modifications: |
(1) A written amendment
of the contract documents signed by both parties. (2) A change order.
(c) A written clarification or interpretation issued by the engineer
in accordance with the terms of the contract. (d) A written order
for a minor change or alteration in the work issued by the engineer
pursuant to the terms of the contract. A modification may only be
issued after execution of the agreement. |
| Modified
sliplining: |
A range of techniques
in which the liner is reduced in cross sectional diameter before insertion
into the Carrier
Pipe. It is subsequently restored to close to its original diameter,
generally forming a close fit with the original pipe. Methods of cross
sectional area reduction include squeezing, folding into a U-shape
or stretching. See lining
with close-fit pipes. |
| Modulus
of elasticity (E): |
The stress required
to produce strain, which may be a change of length (Young's modulus);
a twist or shear (modulus); a twist or sheat (modulus or rigidity);
or a change of volume (bulk modulus), expressed in dynes per square
centimeter. |
| Mole : |
See impact
moling. |
| Mole
ploughing: |
Burying a pipeline
by pulling a plough through the ground while a continuous length of
pipe is fed into the top of the plough and laid out underground from
the tail of the plough. An alternate ploughing technique may use a
plough blade with a bullet at the end to create a tunnel beneath the
surface into which a pipe may be pulled. |
| Molecular
weight distribution: |
The ratio of the weight
average molecular weight to the number average molecular weight. This
gives a preliminary indication of the range of molecular weights. |
| Moling: |
A minimum excavation
procedure for the construction of pipelines. In collection system
re-engineering, moling is typically used as a form of on line replacement,
breaking aside the existing sewer fabric and pulling through a new
structural lining. |
| Moment
of Inertia: |
Function of some property
of a body or figure - such as weight, mass, volume, area, length,
or position, equal to the summation of the products of the elementary
portions by the squares of their distances from a given axis. |
| Moment,
Bending: |
The moment which
produces bending in a beam or other structure. It is measured by the
algebraic sum of the products of all the forces multiplied by their
respective lever arms. |
| Muck: |
As a noun, it means
the same as spoil. As a verb, it means to dig as in "muck out the
hole." |
| Multiple
ring brick sewer: |
A brick sewer that
consists of three or more layers of bricks. |
| Multistaged
new installation |
To plan and undertake
projects with regard to a phased/milestone schedule. |
|
|
|
| Narrow
trenching: |
Method of excavation
of a trench up to 100mm wider than the outside diameter of the service
to be installed, usually employing either a rockwheel or chain type
trencher. |
| Neutral
axis: |
An axis of no stress. |
| Nominal
size: |
Size of pipe or shaft
used to define the internal working diameter. |
| Nominalize: |
To classify a value
into an established range or category. |
| Non-man
entry: |
Size of pipe, duct
or bore less than that for man-entry. |
| Non-uniform
corrosion: |
Corrosion that attacks
small, localized areas of the pipe. Usually results less metal loss
than uniform corrosion but causes more rapid failure of the pipe due
to pits and holes. |
| Notch
sensitivity: |
The extent to which
an inclination to fracture is increased by a notch, crack, scratch,
or sudden change in section. |
| Notice
of award: |
The written notice
by owner to the apparent successful bidder stating that upon compliance
with the conditions precedent to be fulfilled by him within the time
specified, the owner will execute and deliver the agreement to him. |
| Notice
to proceed: |
NTP, a written notice
given by the owner to the contractor (with a copy to the engineer)
fixing the date on which the contract time will commence to run and
on which contractor shall start to perform his obligations under the
contract documents. |
|
|
|
| Obstruction: |
Any object or feature
that lies completely or partially within the cross section of the
microtunnel and prevents continued forward progress. |
| Ogee: |
A joint with an elongated
"S" profile within the thickness of a sewer pipe wall. |
| Oiler: |
Changes amount of lubricating
oil injected in supply air. |
| OPC: |
Ordinary Portland
Cement; customarily used for making concrete, mortar and grout in
non-aggressive conditions. |
| Open cut: |
The method by which
access is gained to the required level underground for the installation,
maintenance or inspection of a pipe, conduit or cable. The excavation
is then backfilled and the surface restored. See conventional
trenching. |
| Open
face shield: |
Shield in which manual
excavation is carried out from within a steel tube at the front of
a pipe jack. |
| Operator
presence control: |
A control or mechanism
designed so that operator presence is necessary to activate a specific
function. |
| Orangeburg: |
Orangeburg is a bituminized
fiber pipe. Manufactured as an alternative to metal pipe in response
to a metal shortage due to World War II. The life expectancy from
experience is about 25 years. This type of pipe has been known to
collapse often necessitating replacement. |
| Organic
debris: |
Production waste and
other material that accumulates in sewers or manholes. |
| OSHA: |
Occupational Safety
and Health Administration. |
| Other
sewer structures: |
Other portions of the
industrial sewer pipelines and manholes, including trap tanks, sumps,
and any other structure not specifically identified. |
| Outfall: |
An outlet to a sewer
system. |
| Ovality: |
There are two options:
a) the difference between the maximum and mean diameter divided by
the mean diameter, and b) the difference of the mean and minimum divided
by the mean, at any one cross section of a pipe, generally expressed
as a percentage. |
| Overcut: |
The annular space
between the excavated hole and the outside diameter of the jacking
pipe. |
| Overflow: |
(1) The excess water
that flows over the ordinary limits of a sewer, manhole, or containment
structure. (2) An outlet, pipe, or receptacle for the excess water. |
| Owner: |
A public body of
authority, corporation as partnership, or individual for whom the
work in to be performed. |
| Oxidation: |
Loss of electrons,
as when a metal goes from the metallic state to the corroded state. |
|
|
|
| Packer: |
See Compression
ring. |
| Parapet: |
Wall or rampart, breast
high. Also, the wall on top of an abutment extending from the bridge
seat to the underside of the bridge floor and designed to hold the
backfill. |
| Pascal's
Law: |
Pressure exerted
at any point upon a confined liquid is transmitted undiminished in
all directions. |
| Pavement,
Invert: |
Lower segment of a
corrugated metal pipe provided with a smooth bituminous material that
completely fills the corrugations, intended to give resistance to
scour, erosion, and to improve flow. |
| PE: |
Polyethylene; a form
of thermoplastic pipe. |
| Percent
(%): |
A dimensionless number
with the ratio of one (1) to one hundred (100). In the construction
industry, it is mostly used to give the rise of fall of a pipe line,
or road, in feet per 100 feet (i.e., a one (1) foot rise in one hundred
(100) feet would be a plus 1% (one percent) grade). |
| Perched
water table: |
In hydrology, the
upper surface of a body of free ground water in a zone of saturation,
separated by unsaturated material from an underlying body of ground
water in a differing zone of saturation. |
| Periphery: |
Circumference or perimeter
of a circle, ellipse, pipe-arch, or other closed curvilinear figure. |
| Permeability: |
Penetrability. |
| PFA: |
Pulverized Fuel Ash;
a fine powder residue after burning carbon based products. Especially
from electricity generating stations. |
| pH: |
A measure of the
acidity or alkalinity of a solution. A value of seven is neutral;
low numbers. |
| Physical
pipe inspection: |
The crawling or walking
through manually accessible pipe lines. The logs for physical pipe
inspection record information of the kind detailed under TELEVISION
INSPECTION. Manual inspection is only undertaken when field conditions
permit this to be done safely. Precautions are necessary. |
| Piercing
tool: |
An impact type of
compacting device for boring. |
| Pile,
Bearing: |
A member driven or
jetted into the ground and deriving its support from the underlying
strata and/or by the friction of the ground on its surface. |
| Piling: |
Rigid supports, driven
vertically to provide wall support in the pit. |
| Pilot
bore: |
The action of creating
the first (usually steerable) pass of any boring process which later
requires back-reaming or similar enlarging. Most commonly applied
to Guided
Boring, Directional
Drilling and 2-pass microtunneling systems. |
| Pilot
Tube Method: |
A multi-stage method
of accurately installing a product pipe by use of a guided pilot tube
and followed by upsizing to install the product
pipe. |
| Pins: |
See shank. |
| Pipe
: |
A long tube of clay,
concrete, steel, metal, wood, etc., for conveying water, gas, oil
or other materials. |
| Pipe bursting: |
A replacement method.
A technique for breaking the existing pipe by brittle fracture, using
force from within, applied mechanically, the remains being forced
into the surrounding ground. At the same time a new pipe, of the same
or larger diameter, is drawn in behind the bursting tool. The pipe
bursting device may be based on an Impact
Moling tool to exert diverted forward thrust to the radial bursting
effect required, or by a hydraulic device inserted into the pipe and
expanded to exert direct radial force. Generally a PVC or HDPE pipe
is used. Also known as Pipe
Cracking and Pipe
Splitting. |
| Pipe
displacement: |
Term used in North
America. See Pipe
Bursting. |
| Pipe drilling
cracking: |
See pipe
bursting. |
| Pipe
eating: |
A replacement technique,
usually based on microtunneling,
in which a defective pipe is excavated together with the surrounding
soil as for a new installation. The microtunneling shield machine
will usually need some crushing capability to perform effectively.
The defective pipe may be filled with grout to improve steering performance.
Alternatively, some systems employ a proboscis device to seal the
pipe in front used of the shield to collect and divert the existing
flow, thus allowing a sewer, for example, to remain "live". |
| Pipe jacking: |
A system of directly
installing pipes behind a shield
machine by hydraulic jacking from a drive
shaft such that the pipes form a continuous string in the ground. |
| Pipe
joint sealing: |
A method of sealing
leaking or defective pipe joints which permit infiltration of groundwater
into sewers by means of injecting chemical grout into and/or through
the joints from within the pipe. |
| Pipe lubricant: |
See Lubrication. |
| Pipe
pulling: |
Method of replacing
small diameter pipes where a new product pipe is attached to the existing
pipe which is then pulled out of the ground. |
| Pipe pusher: |
A machine that pushes
or pulls a rod or pipe to produce a bore by means of compaction without
rotation or impact. |
| Pipe
ramming: |
A non-steerable system
of forming a bore by driving an open-ended steel casing
using a percussive hammer from a Drive
Pit. The soil may be removed from the casing by augering, jetting,
or compressed air. |
| Pipe segment: |
A specific portion
of the sewer system piping; usually runs between two structure (e.g.,
manhole, trap tanks, sumps); identified with unique sewer structure
ID number. |
| Pipe
splitting: |
Replacement method
for breaking an existing pipe by longitudinal slitting. At the same
time a new pipe of the same or larger diameter may be drawn in behind
the splitting tool. See also Pipe
Bursting. |
| Pipeline
(also pipe): |
Portions of the sewer
system that are constructed of piping as opposed to manholes and other
structures (e.g., trap tank, sumps, etc.). |
| Pipeline
reconstruction: |
The Insitu repair
of an existing pipeline that has suffered loss of pressure integrity
or has been structurally damaged. The liner becomes the principal
pressure containment or structural element of the Insitu composite
pipe structure. |
| Pipeline
rehabilitation: |
The insitu repair of
an existing pipeline, which has become corroded or abraded, by insert
renewal of a liner which rehabilitates the bore of the pipeline but
does not contribute significantly to increased pressure capability
or increased structural strength, yet does improve flow efficiency/hydraulics. |
| Pipeline
system: |
Interconnecting pipe
network for the conveyance of fluids. |
| Pitting
Factor: |
The depth of the deepest
pit divided by the "average penetration" as calculated from weight
loss. |
| Pitting: |
Highly localized
corrosion resulting in deep penetration at only a few spots. |
| Planner: |
Individual who defines
and schedules maintenance (including inspection) activities and provide
coordination between operations and work groups. |
| Planting
piping: |
Installation procedure
that digs a trench and lays the pipe in one step. |
| Plastic: |
Any of a variety of
thermoplastic and thermoset material used in sewer construction (e.g.,
high-density polyethylene, polypropylene, PVC, fiberglass reinforced
plastics, polyester felt reinforced pipe, epoxy and polyester mortars,
etc). |
| Plasticizer: |
An admixture to cement
to make a mix more fluid without the addition of more water. |
| Plate: |
A flat-rolled iron
or steel product. |
| Plough-in
piping: |
Installation procedure
that splits the earth and pulls the pipe into position. |
| Point
source repair: |
See localized
repair. |
| Pointing: |
Method of repairing
a brick sewer or manhole by the application of cement mortar where
loss has occurred. |
| Polyester: |
Resin formed by condensation
of polybasic and monobasic acids with polyhydric alcohols. |
| Polyethylene: |
A ductile, durable,
virtually inert thermoplastic composed by polymers of ethylene. It
is normally a translucent, tough solid. In pipe grade resins, ethylene-hexene
copolymers are usually specified with carbon black pigment for Weatherability. |
| Polyolefin: |
A family of plastic
material used to make pipes. |
| Polypropylene: |
A type of plastic
pipe from the polyolefin family. (abbrev. PP) |
| Ponding: |
Jetting or the use
of water to hasten the settlement of an embankment - requires the
judgment of a soils engineer. In hydraulics, pending refers to water
backed up in a channel or ditch as the result of a culvert of inadequate
capacity or design to permit the water to flow unrestricted. |
| Potholing: |
Digging of a hole
to locate a utility. |
| Power
package: |
The engine and drive
section of a split boring machine or the remote engine and hydraulic
pumps of a power unit. |
| Power
requirements: |
Manufacturer¡¦s
recommend maximum flow and pressure. |
| PPI (Plastic
Pipe Institute): |
A division of The Society
of the Plastics Industry, Inc. |
| PRC: |
Polyester Resin Concrete. |
| Precipitation: |
Process by which water
in liquid or solid state (rain, sleet, snow) is discharged out of
the atmosphere upon a land or water surface. |
| Preconditioning
work: |
That part of a project,
usually before renovation work, which includes Preparatory
Cleaning and Internal
Inspection. |
| Preparatory
cleaning: |
Internal cleaning of
pipelines, particularly sewers, prior to inspection, usually with
water jetting and removal of material where appropriate. |
| Pressure
rating: |
Estimated maximum
internal pressure that allows a high degree of certainty that failure
of the pipe will not occur. |
| Pressure: |
Changes the drilling
fluid pressure. |
| Pressurized: |
To pump or force
a liquid at a higher rate than that achievable under normal open channel
or free surface conditions. |
| Preventative:
|
Routine maintenance
designed to prevent sewer system maintenance problems. |
| Primary
pipe: |
The basic conduit
when used in conjunction with a "protective liner"; when inspected
and evaluated it is the basic or primary pipe which must meet the
fit-for-use criteria. When a sewer section is upgraded with a structural,
monolithic liner, the liner becomes the primary pipe; subsequent inspection
and evaluation is then performed with respect to that liner. |
| Primary
properties: |
The properties used
to classify polyethylene materials. |
| Prioritization: |
To list in descending
order of urgency/action |
| Priority
classification (priority rating): |
A rating system based
on the characteristics of the wastewater conveyed in any sewer structure;
sewers carrying hazardous waster have higher priorities ( lower numbers);
sewers with special process or location risks carry higher priorities. |
| Privatize: |
To take out of public
operation or ownership; to instigate private sector participation
in the financing and/or operation and/or maintenance and/or ownership
of public assets, such as treatment plants and collection systems,
for example. |
| Proactive: |
To adopt a positive
role towards ensuring effective solutions. To anticipate and control
events; the opposite of reactive. Probing by auger or coring tool,
usually vertically, at the site to determine soil conditions. |
| Product
Pipe: |
Permanent pipeline
for opertational use. Pipe for conveyance for water, gas, sewage,
and other products. |
| Profile: |
Anchor pattern on a
surface produce by abrasive, blasting or acid treatment. |
| Project: |
The entire construction
to be performed as provided in the contract documents. |
| Protruding: |
To be projecting outward. |
| PSI: |
Pounds per Square
Inch. US customary unit for pressure. One PSI equals 6.896 Kilonewtons
per square meter. |
| Pull back: |
That part of a guided
boring or directional
drilling operation in which the drill
string is pulled back through the bore to the entry
pit or surface rig, usually installing the product
pipe at the same time. |
| Pull
back force: |
The tensile load
applied to a drill string during the pull back process. Guided boring
and directional drilling rigs are generally rated by their maximum
pull-back force. |
| Pull-in
piping: |
Also referred to as
insert renewal; installation procedure whereby pipe is pulled inside
old mains and service lines to provide the new main or service line. |
| Pump,
sewage ejector: |
See Sewage
ejector pump. |
| Pump,
sewage grinder: |
See Sewage
grinder pump. |
| Push
bar: |
See thrust
block. |
| Push block: |
See thrust
block. |
| Push
package: |
See thrust
package. |
| PVC: |
Polyvinyl Chloride;
a form of thermoplastic Pipe. |
|
|
|
| Radian: |
An arc of a circle
equal in length to the radius; or the angle at the center measured
by the arc. |
| Radius
of gyration: |
The distance from the
reference at which all of the area can be considered concentrated
that still produces the same moment of inertia. Numerically it is
equal to the square root of the moment of inertia, divided by the
area. |
| Rainfall: |
Precipitation in
the form of water (usage includes snow). |
| Ramming: |
A percussive hammer
is attached to an open end casing, which is driven through the ground.
The spoil within the casing is removed to leave an open casing. |
| Ranking: |
To assign a relative
position to competing items. |
| Ratepayers: |
Terminology used by
lawmakers to refer to utility customers responsible for paying for
service. |
| Receiving
pit: |
(1) See exit pit.
(2) An opening in the earth located at the expected exit of the cutting
head or casing. (3) (Come out hole, Come out pit) The pit that is
dug at the end of the bore, opposite the Jacking pit. |
| Receiving
shaft: |
See Reception
Shaft. |
| Reception
shaft: |
Excavation into which
the microtunneling equipment is driven and recovered. |
| Reception/exit
shaft/pit: |
Excavation into which
trenchless technology equipment is driven and recovered following
the installation of the Product
Pipe, conduit
or cable. |
| Reduction: |
Gain of electrons,
as when copper is electro-plated on steel from a copper sulfate solution
(opposite of "Oxidation"). |
| Re-engineering: |
All aspects of upgrading
the performance of existing collection systems. Structural re-engineering
includes repair, rehabilitation and renewal. Hydraulic reengineering
covers replacement, reinforcement, flow reduction or attenuation and
occasionally rehabilitation. |
| Reference
groundwater level: |
The reference groundwater
elevation. |
| Regression
analysis: |
An evaluation of the
long-term hoop stress data. A linear curve is calculated using the
least Squares method to fit the logarithm of hoop stress versus the
logarithm of the resulting hours-to-failure. |
| Regulator: |
A device for controlling
the quantity of sewage and storm water admitted from a combined sewer
collector line into an interceptor, pump station or treatment facility,
thereby determining the amount and quality of the flow discharged
through an overflow device to receiving waters or other points of
disposal. |
| Rehabilitation: |
(1) All methods for
restoring or upgrading the performance of an existing pipeline system.
(2) Methods by which the performance of a length of sewer is improved
by incorporating the original sewer fabric, but excluding maintenance
operations such as tree root or silt removal. Or rehabilitation In
situ renovation to improve the performance and extend the life of
a defective pipeline, incorporating the fabric of that pipeline. Rehabilitation
may be to address structural and/or hydraulic weakness. |
| Reinforcement: |
The provision of
an additional sewer which in conjunction with an existing sewer increases
overall flow capacity. |
| Reinstatement: |
Method of backfilling,
compaction and re-surfacing of any excavation in order to restore
the surface and underlying structure to enable it to perform its original
function. |
| Remote
control system: |
The remote control
system monitors and controls the MTBM, the automated transport system,
and the guidance system from a location not in the MTBM. |
| Renewal: |
Construction of a new
sewer, on or off the line of an existing sewer. The basic function
and capacity of the new sewer being similar to the original. |
| Renovation: |
Methods of rehabilitation
in which all or part of the original fabric of a pipeline are incorporated
and its current performance improved. |
| Repair: |
Rectification of damage
to the structural fabric of the sewer, or the reconstruction of short
lengths, but not the reconstruction of a whole pipeline. |
| Replacement: |
Construction of a
new sewer, on or off the line of an existing sewer. The function of
the new sewer will incorporate that of the old, but may also include
other improvements or development work. |
| Rerounding: |
A preparatory process
which involves the insertion of an expansion device into a distorted
pipe to return it to a circular cross section. This is usually carried
out prior to the insertion of a permanent liner or supporting band. |
| Resin
impregnation (wet-out): |
A process used in
cured-in-place pipe installation where a plastic coated fabric tube
is uniformly saturated with a liquid thermosetting resin while air
is removed from the coated tube by means of vacuum suction. |
| Resin
injection: |
The localized
repair of pipes, usually sewers, by injection of a resin formulation
into cracks or cavities which subsequently cures to prevent leakage
and further deterioration. It may also increase the structural strength
of the pipeline. |
| Resins: |
An organic polymer,
solid or liquid; usually thermoplastic or thermosetting |
| Restoration: |
The backfilling, compaction
and re-surfacing of any excavation in order to restore the surface
and underlying structure to enable it to perform its original function. |
| Retract: |
The motion of the
machine away from the face of the entrance pit. |
| Reverse: |
The counter-clockwise
rotation of the auger as viewed from the machine end. |
| Reversing
procedure: |
Procedure for reversing,
if applicable |
| Revetment: |
A wall or a facing
of wood, willow mattresses, steel units, stone or concrete placed
on stream banks to prevent erosion. |
| Reynolds
number: |
A dimensionless quantity
named after Osbourne Reynolds who first made know the difference between
laminar and turbulent flow. The practical value of the Reynolds Number
is that it indicated the degree of turbulence in a flowing liquid.
It depends on the hydraulic radius of the conduit, the viscosity of
the water and the velocity of flow. For a conduit of a given size,
the velocity is generally the major variable and the Reynolds Number
will increase as the velocity of flow increases. |
| RII: |
Rainfall Induced Infiltration;
is a particular form of infiltration which is similar to stormwater
inflow. RII generally occurs during and immediately after rainfall
events. |
| Ring
compression: |
The principal stress
in a confined thin circular ring subjected to external pressure. |
| Rip rap: |
Rough stone of various
sizes placed compactly or irregularly to prevent scour by water or
debris. |
| Riser: |
A thin ring located
between the frame and cone of a manhole. Used to bring the frame and
cover final grade. Commonly, several riser are present in a manhole. |
| Robot: |
Remote control device
with closed circuit television (CCTV) monitoring, used mainly in localized
repair work, such as cutting away obstructions, re-opening lateral
connections, grinding and re-filling defective areas and injecting
resin into cracks and cavities. |
| Rod
pushing: |
Method of forming
a pilot bore by driving a closed pipe head with rigid attachment from
a launch pit into the soil which is displaced. Limited steering and
monitoring capability may be provided, usually in conjunction with
a locator. See thrust
boring. |
| Rods: |
Either flexible poles,
fiberglass or wood for example, for removing blockages in sewers;
or graduated measuring devices for estimating internal sewer dimensions. |
| Roller
cone bit or reamer: |
A bit or reamer in
which the teeth rotate on separate, internal shafts that are usually
aligned perpendicular to line. Used for boring rock. |
| Roof leader: |
A drain or pipe that
conducts storm water from the roof of a structure downward and thence
into a sever for removal from the property, or onto the ground for
runoff or seepage disposal. |
| Rotary
rod machine: |
A machine used to
drill earth horizontally by means of a cutting head attached to a
rotating rod (not an auger).
Such drilling may include fluid injected to the cutting head through
a hollow rod. |
| Rotation
controls: |
Those controls that
control the direction and/or the rotation of the tool. |
| Rotation
speed: |
The speed at which
the rod turns. |
| Roughness
coefficient: |
A factor in the Kutter,
Manning, and other flow formulas representing the effect of channel
(or conduit) roughness upon energy losses in the flowing water. |
| RPM: |
Reinforced Plastic
Mortar; a form of thermoset plastic pipe |
| RTR: |
Reinforced Thermosetting
Resin; a form of thermoset plastic pipe within the GRP family. |
| Runoff: |
That part of precipitation
carried off from the area upon which it falls. Also, the rate of surface
discharge of the above. That part of precipitation reaching a stream,
drain or sewer. Ratio of runoff to precipitation is a "coefficient"
expressed decimally. |
|
|
|
| Saddle
machine: |
See cradle
machine. |
| Saddle:
|
A vertical support
mechanism to hold the casing in position while starting (collaring)
the bore. |
| Safety
factor: |
As used in determining
reinspection interval; a fractional multiplier, based on priority
rating, to ensure sewer segment reinspection prior to becoming not
fit for use. |
| Safety
glasses: |
Eye protection to
be worn at all times. |
| Safety
sign: |
A notice attached to
the machine which advises the nature and severity of a potential hazard
which can cause injury or death. It can also provide instructions
to reduce or eliminate the hazard. |
| Samples: |
Physical examples
which illustrate materials, equipment or workmanship and establish
standards by which the work will be judged. |
| Sanitary
sewer: |
A sewer that conveys
the wastewater from two or more properties. |
| Scaling: |
High temperature
corrosion resulting in formation of thick corrosion product layers.
Deposition of insoluble materials on metal surfaces, usually inside
water boilers or heat exchanger tubes. |
| SDR: |
See Standard
Dimension Ratio. |
| Seal:
|
A water-tight bond. |
| Secondary
stress: |
Forces acting on the
pipe in addition to the internal pressure such as those forces imposed
due to soil loading and dynamic soil conditions. |
| Section
modulus: |
The moment of inertia
of the area of a section of a member divided by the distance from
the center of gravity to the outermost fiber. |
| Sectional
properties: |
End area per unit of
widths, moment of inertial, section modulus, and radius o gyration. |
| Sediment
debris: |
Specifies the extent
of the problem (defect) based on the judgment of the field crew. |
| Sediment: |
Particles that settles
on the pipe invert, causing a reduction in cross sectional area. |
| Seepage: |
Water escaping through
or emerging from the ground along rather extensive line or surface,
as contrasted with a spring, the water of which emerges from a single
spot. |
| Seeper: |
Applied to infiltration
during the first stages to quantify the slow ingress of water into
a sewer through a defect or faulty joint. |
| Segmental
concrete tunnel liner: |
Used the same way
as Liner Plate except that they are tunnel liners made of concrete. |
| Segmental
lining: |
The use of prefabricated
segments in Man-Entry
work to form a new lining within a defective pipe. The segments are
usually sealed at the joints and the annulus is grouted. See lining
with pipe segments. |
| Segmental
sliplining: |
See sliplining.
See lining
with discrete pipes. |
| Self-cleansing: |
A consequence of good
hydraulic design when the pipe invert is kept relatively free of sediments
by ensuring adequate flow velocities. |
| Separate
system: |
A system that uses
sanitary sewers to convey the wastewater and stormwater sewers to
carry the stormwater. |
| Serviceability
of the piping system: |
Continued service life
with a high degree of confidence that a failure will not occur during
its long-term service. |
| Settlement: |
See Subsidence. |
| Sewage
: |
Wastewater transported
in a sewer. |
| Sewage
ejector pump: |
A sewage ejector
pump is used to pump wastewater to an elevation whereby the wastewater
can flow by gravity to the sewer. |
| Sewage
grinder pump: |
A sewage grinder pump
will discharge a finely ground slurry into a small diameter pressure
pipe. In a low pressure sewer system (LPSS) all the piping downstream
of the grinder pump will normally be under low pressure, 60psi or
less. |
| Sewer
: |
An underground pipe
or conduit
for transporting stormwater and/or wastewater. |
| Sewer
building: |
The conduit which connects
building wastewater sources to the public or street sewer, including
lines serving homes, public buildings, commercial establishments and
industry structures. In this specification, the building sewer is
referred to in two sections: (1) the section between the building
line and the property line, frequently specified and supervised by
plumbing or housing officials; and (2) the section between the property
line and the street sewer, including the connection thereto, frequently
specified and supervised by sewer, public works, or engineering officials
(Referred to also as "house sewer", "building connection", or "service
connection"). |
| Sewer
cleaning: |
The utilization of
mechanical or hydraulic equipment to dislodge, transport, and remove
debris from sewer lines. |
| Sewer
cleaning: |
The utilization of
mechanical or hydraulic equipment to dislodge, transport, and remove
debris from sewer lines. |
| Sewer
Inspection : |
Computer database
used to store information about the Information Center sewer system. |
| Sewer
Inspection Information System Group (SIIC): |
Location where inspectors
store and maintain inspection results, etc. |
| Sewer
interceptor: |
A sewer which receives
the flow from collector sewers and conveys the wastewaters to treatment
facilities. |
| Sewer
lateral: |
A building sewer (sometimes
referred to as a sewer lateral or house lateral) is the pipeline between
the County sanitary sewer line, which is usually located in the street,
and the indoor plumbing. County sanitary sewer lines have a pipe inside
diameter of 8" or greater while building sewers have a pipe inside
diameter of less than 8". Generally, residential building sewers have
a pipe inside diameter of 4" while building sewers for business establishments
have a pipe inside diameter of either 4" or 6". The residential building
sewer is owned and maintained by the property owner even if it extends
into the street or public right of way. |
| Sewer
pipe: |
A length of conduit,
manufactured from various materials and in various lengths, that when
joined together can be used to transport wastewaters from the points
of origin to a treatment facility. Types of pipe are: Acrylonitrile-butadiene-styrene
(ABS); Asbestos-Cement (AC); Brick Pipe (BP); Concrete Pipe (CP);
Cast Iron Pipe (CIP); Polyethylene (PE); Polyvinylchloride (PVC);
Vitrified Clay (VC). |
| Sewer
structure: |
Any portion of the
industrial sewer system including pipeline segments, trap tanks, sumps
and other structures; each are assigned a unique number. |
| Shaft: |
A pit or wall sunk
from the ground surface into a tunnel for the purpose of furnishing
ventilation or access to the tunnel. |
| Shank: |
A hardened male hex
bar, containing one or more transverse holes, to couple and hold in
a female hex connector. |
| Sheet
piling: |
See piling. |
| Sheeting: |
A wall of metal plates
or wood planking to keep out water, soft or runny materials. |
| Shield: |
A steel cylinder
at the face of a utility tunnel or casing, which may sometimes employ
the use of a mechanical excavator and may be steerable, and provide
hazard protection from the area covered. |
| Shield
tunneling method: |
Method of excavation
in the front of a tunnel or pipe jack using a shield. |
| Shop
drawings: |
All drawings, diagrams,
illustrations, brochures, schedules, and other data which are prepared
by the contractor, a subcontractor, manufacturer supplier or distributor
and which illustrate the equipment, materials or some portion of the
work as required by the contract documents. |
| Shoring: |
See piling. |
| Single
ring brick sewer: |
A brick sewer which
consists of a single layer of bricks. |
| Siphon: |
A pressurized length
within a gravity sewer pipeline driven by a higher liquid elevation
at the upstream end. Often used to traverse below rivers, for example,
and avoid the use of pumps. |
| Site
: |
Any location where
work has been or will be done. |
| Site access: |
An adequately clear
area of a size sufficient to accommodate personnel and equipment required
at the location where work is to be performed, including roadway or
surface sufficiently,, unobstructed to permit conveyance of vehicles
from the nearest paved roadway to the work location. |
| Skew
(or Skew Angle): |
The acute angle formed
by the intersection of the line normal to the centerline of the road
improvement, with the centerline of a culvert or other structure. |
| Skin friction: |
Resistance to thrust
caused by soil pressure around the casing.
|
| Sleeve
pipe: |
A pipe installed
as external protection to a product
pipe. |
| Slide: |
Movement of a part
of the earth under force of gravity. |
| Slime
shield: |
Earth pressure balance
shield with soil conditioning additives to facilitate the excavation
of the ground. |
| Slipline: |
A rehabilitation technique
covering the insertion of one pipe inside an existing pipe. |
| Sliplining: |
(1) General term
used to describe methods of lining
with continuous pipes and lining
with discrete pipes. (2) Insertion of a new pipe by pulling or
pushing it into the existing pipe and grouting the annular space.
The pipe used may be continuous or a string of discrete pipes. This
latter is also referred to as Segmental
Sliplining. |
| Slurry
Chamber: |
Located behind the
cutting head of a slurry microtunneling
machine. Excavated material is mixed with slurry in the chamber for
transport to the surface. |
| Slurry
Line: |
A series of hoses
or pipes that transport tunnel muck and slurry from the face of a
slurry microtunneling machine to the ground surface for separation. |
| Slurry
Separation: |
A process where excavated
material is separated from the circulation slurry. |
| Slurry
shield method: |
Method using a mechanical
tunnelling shield with closed face which employs hydraulic means for
removing the excavated material and balances the ground water pressure.
See also Earth Pressure Balance Machine. |
| Slurry: |
A fluid, normally water,
used in a closed loop system for the removal of spoil and for the
balance of groundwater pressure during microtunneling. |
| Smooth
radius bend: |
A contoured sweep
or bend with no sharp or angular sections. |
| Social
costs: |
Costs incurred by society
as a result of collection system works. These include business losses
due to road closures, and the cost of extended journey times due to
traffic delays and diversions. |
| Socket: |
See female hex connector. |
| Soft lining |
See Cured-In-Place
Pipe (CIPP) or Lining
with Cured-in-place pipes. |
| Softening
temperature: |
There are many ways
to measure the softening temperature of a plastic. The commonly reported
Vicat Softening Temperature method is to measure the temperature at
which penetration of a blunt needle through a given sample occurs
under conditions specified in ASTM D 1525. |
| Solar
radiation: |
The emission of light
from the suns, including very short ultraviolet wavelengths, visible
light and very long infrared wavelengths. |
| Solubility: |
The amount of one
substance that will dissolve in another to produce a saturated solution. |
| Sonde
housing |
This integral unit
is the direction drill head which also houses the sonde radio sending
unit. |
| Spacer
block: |
Device used to extend
the distance that the hydraulic rams within a jacking system can propel
the pipeline. |
| Spacers: |
See Compression
ring. |
| Spalling: |
(1) A process that
describes the flaking, or slitting away of the surface layer. (2)
The spontaneous chipping, fragmentation, or separation of a surface
or surface coating. |
| Span: |
Horizontal distance
between supports, or maximum inside distance between the sidewall
of culverts. |
| Special
Conditions: |
When included as
a part of the contract documents. Special conditions refer only to
the work under this contract. |
| Specific
gravity: |
The density of a material
divided by the density of water usually at 4?/font> C. Since the density
of water is nearly 1 g/cm3, density in g/cm3 and specific gravity
are numerically nearly equal. |
| Specifications: |
Those portions of
the contract documents consisting of written technical descriptions
of materials, equipment, construction systems, standards and workmanship
as applied to the work. |
| Speed
controls: |
Those controls that
control the speed of the engine, rotation of the tool, travel of tool,
and forward or lateral movement of the machine. |
| Speed
reducer: |
See final
drive. |
| Spelter: |
Zinc or galvanized
coating on steel products. |
| SPG: |
Structural Performance
Grade; used to generate a final structural condition classification
for sewer lengths. Recognizes the impact of external factors: surrounding
soil conditions; frequency of surcharging, for example, and relates
these to the Internal Condition Grade (ICG). |
| Spillway: |
A low-level passage
serving a dam or reservoir through which surplus water may be discharged;
usually an open ditch around the end of a dam, a gateway, or a pipe
in a dam. - An outlet pipe, flume or channel serving to discharge
water from a ditch, ditch check, gutter or embankment protector. |
| Spiral
lining: |
A technique in which
a ribbed plastic strip is spirally wound by a winding machine to form
a liner which is inserted into a defective pipeline. The annular space
may be grouted or the spiral liner expanded to reduce the annulus
and form a Close-Fit
liner. In larger diameters, the strips are sometimes formed into panels
and installed by hand. Grouting the annular space after installation
is recommended. See Lining
with spirally wound pipes. |
| Spiral
weld pipe (casing): |
Pipe made from coils
of steel plate by wrapping around a mandrail in such a manner that
the welds are a spiral helix. |
| Split
design: |
A boring machine
having the capability of being broken down into two or more elements
to reduce the lifting weight. |
| Spoil
(muck): |
Earth, rock and other
materials displaced by a tunnel or casing, and removed as the tunnel
or casing is installed. In some cases, it is used to mean only the
material that has no further use. |
| Spoil
chamber: |
See casing
pusher. |
| Spoil
ejector door: |
A door that partially
or completely closes the spoil opening when at rest. |
| Spoil
ejector: |
A set of paddles,
rotating in close proximity to the inside of the casing pusher. |
| Spot repair: |
See localized
repair. |
| Spray
lining: |
A technique for applying
a lining of cement mortar or resin by rotating a spray head which
is winched through the existing pipeline. |
| Springline: |
(1) Also Springing.
An imaginary horizontal line across the sewer that passes between
the points where the sewer has its greatest cross sectional width.
(2) Midpoint of sewer pipe. (The line equal distance between the crown
and the invert of the pipe). |
| Spun
Lining: |
A bituminous lining
in a pipe, made smooth or uniform by spinning the pipe around its
axis. |
| SRPC: |
Sulfate Resisting Portland
Cement; customarily used for making concrete, mortar and grout in
aggressive conditions where sulfates concentrations may be high. |
| SSBS: |
Sanitary Sewer Bypasses;
structures to relieve hydraulic overload on nominally sanitary sewers,
leading to flooding and or pollution of a watercourse. Typically occurring
during wet weather. |
| SSES: |
Sewer System Evaluation
Survey; mainly for inflow and infiltration (I/I) surveys to determine
the degree and location of flows entering the collection system. |
| Stabilization: |
See Chemical
Stabilisation. |
| Stabilizer: |
An ingredient used
in the formulation of some plastics to assist in maintaining the physical
and chemical properties of the materials at their initial values throughout
the processing service life of the material. |
| Stakedown
plate |
A plate staked to
the ground to stabilize the forward end of the drill rack. |
| Standard
dimension ratio: |
SDR, Standard Dimension
Ratio is defined as the ratio of the outside pipe diameter to wall
thickness. |
| Steerable
moling: |
Method similar to
impact moling with a limited steering capability. |
| Steering
head: |
A moveable lead section
of casing that can be adjusted to steer the bore. |
| Stepwise: |
A logical process
carried out in sequence. |
| Stoppage: |
A blockage in the sewer
line that prevents the passage of wastewater. |
| Storm
: |
A rainfall event.
(See also - catastrophic rainfall event.) |
| Storm
mains: |
Primary collector pipelines
in the storm water collection system. |
| Storm
sewer: |
A sewer intended
to carry only storm waters, surface runoffs, street washwaters, and
drainage. |
| Stormwater
sewer: |
A sewer that conveys
stormwater runoff from two or more properties and stormwater runoff
from roofs, paved areas and roads within the catchment area of the
sewer. |
| Strain
rate: |
The rate of lineal
change per unit length. |
| Street
access: |
Areas normally used
for public vehicular traffic (including roads, streets, or rights-of-way)
to which safe access is required for performance of work. |
| Stress
: |
The load applied
per unit area of material. Often expressed as pounds of force per
square inch (psi). |
| Stress
corrosion cracking (SCS): |
Cracking of a metal
produced by the combined action of corrosion and tensile stress (residual
or applied). |
| Stress
life curves: |
Graphic representations
showing the extrapolation to 100,000 hours of applied hoop stress
versus hours to failure data on logarithmic scales per ASTM D 2837. |
| Stress
relieve: |
The decrease in imposed
stresses at a constant strain. In thermoplastic materials it occurs
as a property of the material with time. |
| Stringing: |
Process by which
a line is floated through a sewer segment for later use to pull a
cable for video inspection or cleaning equipment. |
| Structural: |
Physical adequacy to
support imposed loads. |
| Structure
ID: |
A number that defines
a component of the sewer system. |
| Subcontractor: |
An individual, firm
or corporation having a direct contract with contractor or with any
other subcontractor for the performance of a part of the work at the
site - or - An individual, firm or corporation having direct contract
with the contractor or with a lower-tier subcontractor for performance
of part of the work. |
| Subdrain: |
A pervious backfilled
trench containing a pipe with perforations or open joints for the
purpose of intercepting ground water or seepage. |
| Subgrade: |
The surface of a portion
of the roadbed on which paving, or railroad track ballast, or other
structure is placed. |
| Subsidence: |
The settlement of
the ground, pipeline or other structure. The effects may not be evenly
distributed and differential settlement may occur. |
| Substantial
completion: |
The stage in construction
when a project can be utilized for the purposes for which it was intended.
At substantial completion, minor items and items that are seasonally
restricted need not be completed, but the items that affect operational
integrity and function of the facility must be capable of continuous
use. |
| Sulfide
stress cracking (SSC): |
Brittle failure by
cracking under the combined action of tensile stress and corrosion
in the presence of water and hydrogen sulfide. |
| Sump: |
A depression in the
pit to allow for the collection of water and the installation of a
pump for water removal. |
| Supplementary
General Conditions: |
Federal conditions
in effect at time at submission of bid. |
| Supplier: |
Any person or organization
who supplies materials or equipment for the work, inducing that fabricated
to a special designs, but who does not perform labor at the site. |
| Surcharge
: |
When the sewer flow
exceeds the hydraulic carrying capacity of the sewer line. |
| Surcharge
condition: |
When the sewer flow
depth equals or exceeds the diameter of the discharging sewer line. |
| Surcharged
sewer: |
A gravity sewer that
is overloaded beyond its pipe full flow capacity such that the flow
becomes pressurized. |
| Surety: |
The corporate body
which is bound with the contractor and which engages to be responsible
for the contractor and his acceptable performance of the work. |
| Surface
hardness: |
A measure of the
net increase in depth as an indented load is increased from a minor
load to a major load and then returned to a minor load. This is used
as an indication of relative hardness among like materials. |
| Survey
tools: |
Downhole equipment
and instruments used to determine the position of a bore in directional
drilling or in site investigation. |
| Swab
(bull plug): |
A steel plug which
is pulled through a horizontal bore to remove the cuttings. |
| Swageing: |
The reduction in diameter
of a polyethylene pipe by passing it through one or more dies. The
die may be heated if necessary. |
| Swagelining: |
A method of sliplining
whereby the diameter of the PE pipe is temporarily reduced by swageing
prior to insertion in the defective pipe. After insertion, the pipe
is expanded by means of steam or a rerounding device. |
| Swale
(DIP, SAG): |
A significant deviation
In pipe grade such as to cause entrapment of solids, semisolids, and
liquids, thereby impeding the accuracy and/or effectiveness of flow
measurements, cleaning, and internal inspection. |
| Swivel
pulling: |
Used to attach service
(to be pulled into drilled hole) to drill pipe. |
|
|
|
| Tailwater: |
The water just downstream
from a structure. |
| Target
shaft/pit: |
See reception/exit
shaft/pit. |
| Taxpayer: |
Contributions through
taxation to utilities to fund supplied services. |
| TBM: |
See Tunnel
Boring Machine. |
| Teeth: |
See bits. |
| Televise: |
Process by which
a sewer line or lateral is inspected with a Closed-Circuit television
camera. |
| Tensile
Strength At Yield: |
The measured tensile
stress required to initiate permanent deformation in a sample under
the conditions described in ASTM D 638. |
| Tensile
Strength: |
The pulling stress
in psi that is required to elongate a given specimen to the breaking
point. |
| Test Medium: |
The fluid or gas inside
the main being tested. |
| Thermal
Conductivity: |
The ability of a
material to conduct heat; a physical constant for the quantity of
heat that passes through a unit cube of material in a unit of time
when the temperature difference is 1?/font> F. |
| Thermal
Expansion/Contraction: |
The fractional change
in length of a material subjected to a unit change in temperature. |
| Thermal
stabilizers: |
Compounds added to
the plastic resins when compounded that prevent degradation of properties
due to elevated temperatures. |
| Thermography: |
The recording of temperature
variations; a technique to assist in the detection of voids around
pipelines. |
| Thermoplastic: |
A material, such
an polyethylene, that will repeatedly soften when heated and harden
when cooled. |
| Thermoset: |
A material, such as
epoxies, that will undergo or has undergone a chemical reaction by
the action of heat, chemical catalyst, ultraviolet light, etc., leading
to an infusible state. |
| Threading: |
The process of installing
a slightly smaller pipe or arch within a failing drainage structure. |
| Throttle: |
Controls power, speed. |
| Thrust
block pin: |
See dogs. |
| Thrust
block: |
A manual or remote
operated locking mechanism that engages stations in the track to provide
a thrusting base for the machine to advance and retract. |
| Thrust
boring: |
A method of forming
a pilot bore
by driving a closed pipe or head from a thrust
pit into the soil which is displaced. Some small diameter models
have steering capability achieved by a slanted pilot-head face and
electronic monitoring. Back reaming may be used to enlarge the pilot
bore. Also loosely applied to various trenchless installations methods.
See rod pushing. |
| Thrust
jacking method: |
Method in which a pipe
is jacked through the ground without mechanical excavation of material
from the front of the pipeline. |
| Thrust
package: |
The bottom section
of a split boring machine containing the cylinders and thrust block. |
| Thrust
pit: |
See drive
pit. |
| Thrust
Ring: |
A fabricated ring
that is mounted on the face of the jacking frame. It is intended to
transfer the jacking load from the jacking frame to the thrust bearing
area of the pipe section being jacked. |
| Thrust/travel
controls: |
Those controls that
control the advance and retraction of the tool. |
| Thrust: |
Force applied to
a pipeline or drill
string to propel it through the ground. |
| Tile (VT): |
Used to describe products
(sewer pipe and block) manufactured from fired hydrous alumina silicate
clay. |
| Tool
diameter (d): |
Maximum diameter
of tool body |
| Tool length: |
Distance between tip
and end of tool, not including whip hose. |
| Torque
limiter: |
A rotary slip clutch
used to protect the final drive. |
| Torque: |
The rotary force available
at the drive chuck. |
| Track
brake: |
A mechanical device
to provide a limited resistance to movement between the machine and
the track. |
| Track
pins: |
Steel pins to be driven
through holes in the track into the base of the pit. |
| Track
roller: |
See cam
follower. |
| Track: |
A set of longitudinal
rails mounted on cross members that support and guide a boring machine. |
| Transmission: |
A gear reduction
unit located between the power source and final drive. |
| Transportation
System: |
the excavated spoil
from the tunnel face to the surface. |
| Travel: |
Changes travel speed. |
| Trench
box: |
A preconstructed set
of side plates and adjustable cross members to prevent the walls of
the pit from collapsing. |
| Trenching: |
See open
cut or conventional
trenching. |
| Trenchless
technology |
Techniques
for utility line installation, replacement, rehabilitation, renovation,
repair, inspection, location and leak detection, with minimum excavation
from the ground surface. |
| Trunk
sewer |
A sewer into which
at least two branch sanitary, combined or stormwater sewers connect.
It conveys the flow to the Interceptor sewer. The trunk sewer is the
longest connection sewer in any drainage basin. Also sometimes known
as a "main" sewer. |
| Tuberculation |
Localized corrosion
at scattered locations resulting in knob like mounds. |
| Tunnel |
An underground conduit,
often deep and expensive to construct, which provides conveyance and/or
storage volumes for wastewater, often involving minimal surface disruption. |
| Tunnel
boring machine (TBM) |
(1) A full-face circular
mechanized shield machine, usually of Man-Entry
diameter, steerable and with a rotary cutting head. For pipe installation
it leads a string of jacked pipes. It may be controlled from within
the shield or remotely. (2) (Mole, Tunneling Head) A mechanical excavator
used in a tunnel to excavate the front face of the tunnel. |
| Tunneling: |
A construction method
of excavating an opening beneath the ground without continuous disturbance
of the ground surface and of large-enough diameter to allow individuals
access and erection of a ground support system at the location of
material excavation. |
| Two speed
control: |
A hydraulic valve that
increases the flow of oil to the cylinders to provide rapid low power
motion of the machine. |
| Type
"K" barrier rail: |
A portable concrete
fence or barrier that is made in the vague shape of the letter "K". |
|
|
|
| Ultraviolet
Absorbers (Stabilizers): |
Compounds that when
mixed with thermoplastic resin selectively absorb ultraviolet rays
protecting the resins from ultraviolet attack. |
| Uncased
bore: |
Any bore without
a lining or pipe inserted, i.e. self-supporting, whether temporary
or permanent. |
| Underdrain: |
See subdrain. |
| Underground
utility: |
Active or inactive
services or utilities below ground level. |
| Uniform
Corrosion: |
Corrosion that results
in an equal amount of material loss over an entire pipe surface. |
| Upset: |
The inadvertent action
of a boring machine that rotates the machine and track from its normal
and upright position to another position. |
| Upsizing: |
Any method that increases
the cross sectional area of an existing pipeline by replacing with
a larger diameter pipe. |
| Utility
corridor: |
Duct in which two
or more different utility services are installed with access for maintenance.
Commonly referred to as a Utilidor in North America. |
|
|
|
| Valve:
|
Mechanism that controls
the volume or direction of flow Can be closed, partially open, or
fully open. |
| VCP: |
Vitrified Clay Pipe |
| VCT: |
Vitrified Clay Tile
or Vitrified Clay Tile Pipe |
| Velocity
Head: |
For water moving
at a given velocity, the equivalent head through which it would have
to fall by gravity to acquire the same velocity. |
| Virgin
soils: |
Soils which have not
previously been excavated. |
| Voids: |
(1) Holes on the
outside of the pipe in the surrounding soil or material. (2) A term
generally applied to paints to describe holidays, holes, and skips
in the film. Also used to describe shrinkage in castings or welds. |
| Volume: |
The amount of drilling
fluid flow. |
|
|
|
| Wale: |
Guide or brace of
steel or timber, used in trenches and other construction. |
| Walkover
system: |
See locator. |
| Wall: |
Also riser. The vertical
section between the bench and the cone of a manhole. |
| Washover
pipe: |
A rotating drill pipe
of larger diameter than the pilot drill pipe and placed around it
with its leading edge less far advanced. Its purpose is to provide
stiffness to the drilling pipe in order to maintain steering control
over long bores, to reduce friction between the drill
string and the soil and to facilitate mud circulation. See directional
drilling. |
| Waste
ejector: |
See spoil
ejector. |
| Wastewater: |
The liquid conveyed
in sewer system. |
| Water
jetting: |
Method for the internal
cleansing of pipelines using high pressure water jets. |
| Water
level: |
An instrument that
uses a tube filled with water to indicate the elevation of the lead
section of casing. |
| Water
table: |
(1) The elevation
of the ground water. (2) The upper limit of the portion of ground
wholly saturated with water. |
| Watercourse: |
A flowing water body:
ranging in size from a creek to a river, for example. |
| Waterline: |
Maximum liquid level
in a sewer pipe/structure during normal operating cycles. |
| Watershed: |
(1) A defined geographical
area, usually delineated by high ground, that drains to a watercourse.
(2) Region or area contributing to the supply of a stream or lake;
drainage area, drainage basin, catchment are. |
| Weatherability: |
The properties of
a plastic material that allows it to withstand natural weathering;
hot and cold temperatures, wind, rain and ultraviolet rays. |
| WEF: |
Water Environment Federation. |
| Weir
manhole: |
A manhole that contains
a weir used to measure flow. |
| Wetout:
|
The process of injecting
resin into, and distributing it throughout, a hose or tube which will
then be installed into the pipeline and cured in place. |
| Wetted
Perimeter: |
The length of the
perimeter in contact with the water. For a circular pipe of inside
diameter "d", flowing full, the wetted perimeter is the circumference,
d. The same pipe flowing half full would have a wetted perimeter of
d/2. |
| Winch: |
Mechanical device used
to pull the CCTV cameras or cleaning tools through a sewer pipe. |
| Wing
cutters: |
Appendages on cutting
heads that will open to increase the cutting diameter of the head
when turned in a forward direction, and close when turned in a reverse
direction. They are used to cut clearance for the casing pipe. |
| Work: |
Any and all obligations,
duties and responsibilities necessary to the successful completion
of the project assigned to or undertaken by contractor under the contract
documents, including all labor, materials, equipment and other incidentals,
and the furnishing thereof. |
| WQS: |
Water Quality Standard;
prescribed attainment targets to ensure suitably clean water. |
| Wrapped
casing: |
A coating on pipe for
protection from corrosion, usually composed of asphalt and asphalt
coated paper. Some coatings may contain plastic, fiberglass, coal
tar, or other materials. |
| Written
Notice: |
The term "notice"
as used herein shall mean and include all written notices, demands,
instructions, claims, approvals, and disapproval required to obtain
compliance with contract requirements. Written notice shall be deemed
to have been duly served if delivered in person to the individual
or to a member of the firm or to an officer of the corporation for
whom it is intended, or to an authorized representative of such individual,
firm or corporation, or if delivered at or sent by registered mail
to the last business address known to him who gives the notice. Unless
otherwise stated in writing, any notice to or demand upon the owner
under this contract shall be delivered to the owner though the engineer. |
| WWTP: |
Wastewater Treatment
Plant. |
|
|
|
| Zones: |
Different areas in
manholes and other structures which are used for defect evaluation. |
