| Term |
Definition |
|
| 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. Ma |
| 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 |
| 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 |
A pipe installed as external protection to a Product Pipe. |
| Casing pipe method |
Method in which a casing, generally steel, is pipe jacked into place, within which a product pipe is inserted later. |
| 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 |
| 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 wh |
| 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 fro |
| 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 |
| 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 |
| 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 |
| 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 |
Around the inner surface of a circular pipe cross section. |
| Circumferential Coefficient of Expansion and Contr |
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. |
| Cleaning |
An action of a boring machine to remove spoil that occurs when the auger is rotating while axially stationary. |
| 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. |
| 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. |
| 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 compr |
| 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, an |
| 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 cons |
| 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 a |
| 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 thi |
| 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 |
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. |
| Cradle machine |
A boring machine typically carried by another machine that uses winches to advance the casing. |
| 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 m |
| 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 |
