Glossary of Piledriving and Foundation Construction Terms
Welcome to the APE Gloassary for piledriving and foundation construction terms. This is a great place to look for terms that you may be unfamiliar with when working with or researching piledriving technologies. This glossary also contains terms unrelated to piledriving, but that are frequently used on and around foundation construction projects. If you have a question or have term that you would like to add and do not know who to call please contact the APE Headquarters in Washington at (800) 248-8498. Business hours are from 8:00 AM to 5:00 PM Pacific Time. For less immediate inquiries, or if you would like an APE sales representitive to get in contact with you, please visit the APE Contact Request Form.
| TERMS | DEFINITIONS |
| Cage | 1. Reinforcing bars preassembled for quick placing in a pile or excavated slurry-wall trench. 2. See Hairpin Lead, Offshore Leads. |
| Caisson | Large Structural chamber utilized to keep soil and water from entering into a deep excavation or construction area. Caissons may be prefabricated and installed by being sunk in place, by adding weight and by systematically excavating blow the bottom of the unit to allow it to sink to the desired depth. See Caisson Pile, Augered Pile, Gow Caisson, Chicago Caisson. |
| Caisson Hammer | A gravity hammer which is mounted on otp of a ciasson and which contains a cushioning system and a rudimentary lead. Also called Tapette. |
| Caisson Pile | 1. Large diameter steel pipe casing which is drilled, driven or vibrated open ended to the required depth. The inside is cleaned out and filled with concrete. The outside pipe may or may not be extracted. 2. Augered pile with or without permanent casing. Also called Drilled Shaft. |
| Caisson Weights | Steel ingots or concrete blocks used to help sink a caisson or for pile test weights. See Kentledge. |
| Calling the PIle | Indicating that the pile has reached specified penetration and/or blow count-that the pile is "home." |
| Cam Rod | A forged steel part suspended in the intermediate head of double-acting mechanical-valve and single-acting hammers which acted upon by the cam throw to throw the valve. |
| Cam Throw | A forged steel part driven into the ram of double-acting mechanical-valve and single-acting hammers which throws the cam rod and valve at the proper point in the stroke. |
| Camel | A floating log timber in front of docks to keep ships away from the dock. |
| Can | A steel pipe pile. |
| Can Lead | See Offshore Lead. |
| Canary | A long rod made of cold rolled steel or rebar with a "U" shaped hook on the end. Used to slide under stacks of material, then rigging of banding is attached to the hook and can be pulled through easily. |
| Cant Hook | The opposite of its name -- a wood handled tool with a hinged hook near the bottom for turning piles or timbers. See Peavy. |
| Cantilever | A portion of a beam overhanging the support. A projecting beam or member supported at only one end. |
| Cap | A steel plate or channel bolted or welded to the top of a pile or piling to transmit and distribute the load of the structure above the group of pilings. |
| Cap and Plumb Post | Used with deteriorated pile bents, usually timber; existing piles are cut off at good material, a cap placed across them and support built up to the structure. |
| Cap Block | See Drive Cap. |
| Cap Material | See Cushion Block. |
| Capillarity | The upward movement of water, due to effects other than gravity, that occurs through the very small void spaces that exist in a soil mass. |
| Capital | Upper part of a column, pilaster, or pier. |
| Capstan | A mechanically or a manually driven vertical winch used with rope or cable. |
| CAPWAP | Title of computer wave equation program standing for "Case Pile Wave Analysis Program" which determines magnitude and distribution of dynamic and static resistance along a pile from field measured strain and acceleration (force and velocity). |
| Case Method | A method that electronically determines static soil resistance by utilization of a field analyzer, which processes measurements of force and acceleration from pile top. Also known as Pile Dynamics. |
| Casing | 1. An open-end steel pipe installed by drilling, driving or vibrating to support the side of a hole. 2. A pipe dropped or driven into an augered pile to prevent caving temporarily. |
| Casing Blows | The blows, usually of a 300 pound hammer falling 18 in. onto a soil sampler casing while making a soil boring. |
| Cast-In-Place | A concrete pile poured (either with or without a metal casing) in its permanent location in the ground. Also called Insitu Pile, Caisson. |
| Cat Head | A rotating power driven spool or winch head. See Driller's Stroke. |
| Catamaran | A wooden float with sides, for carrying wood piles to a floating driver. |
| Cathodic Protection | A means of protecting steel piles from corrosion by providing a consumable anode or by applying an external electrical potential. |
| Caudill Drive Point Pile | Trade name for a thin shell pipe driven with a mandrel striking on the point. |
| Cellular Cofferdam | A structure of interlocking steel sheet piling to make a self-sustaining cofferdam with seperate inside and outside walls. See Circular-Type Cellular Cofferdam and Diapragm-Type Cellular Cofferdam. |
| Centrifuge | In model pile testing a device to approcimate gravity induced horizontal stresses to compensate for scale. |
| cfm | Cubic feet per minute. |
| CGS | Canadian Geotechnical Society. |
| Chair | Device used to support rebars in the proper position during concrete placement. |
| Chamfer Strip | Narrow wood, metal, plastic, or rubber member placed in the outside corners of concrete formwork to produce a chamfer on the corner of the finished member. |
| Champion Splicer | A trade name for a structural connector for splicing H-piles. |
| Chemical Grout | A fluid with chemicals injected into soil or rock to improve its strength, speed of hardening or other desired characteristic, to improve its load-carrying ability to decrease permeability. |
| Cheminite | A brand name for a wood preservative product used on wood piling. |
| Chicago Caisson | A large diameter shaft with vertical timber sheathing sunk in increments as bracing and additional sheathing is installed. May also apply to rectangular shafts. See Gow Caisson. |
| Chill Ring | See Back-Up-Ring. |
| Chimp | Name referred to APE's smallest vibro, Model 3 |
| Chock | A member, usually of timber, used as a seperator between piles or timbers. |
| Choke | A rigging term to take a round turn on a load using a wire strap with one eye on the choke with the bite of the strap sliding through a shackle that is fastened to the other eye. |
| Choker | A wire rope with special end connections used by loggers for choking or rigging logs for lifting or moving. |
| Chord | Top or bottom member of a truss. |
| Chuck Lead | See Offshore Lead. |
| Churn Drill | A method of drilling through difficult overburden or rock employing a heavy percussion type star bit. |
| Circular-Type Cellular Cofferdam | A structure constructed of interlocking steel-sheet piling consisting of circular cells joined with connecting arcs. The arcs are installed after the cells are completed; the cells and arcs are filled with granular soils. See Diaphragm-Type Cofferdam. |
| Circulation | See Reverse Circulation. |
| Clam/Clamshell | Mechanical bucket used with a crane or derrick for handling granular material. Two jaws close by means of a cable or hydraulic action. |
| Clay | Cohesive soils which are firmly coherent, weighty, compact and hard when dry, but stiff, viscid and ductile when moist. Smooth to the touch. |
| Clay Cutter | A percussion boring tool used in clay soiuls. |
| Cluster | A group of piles. |
| Coarse-Grained Soil | Soil types that have particles large enough to be seen without visual assistance. The coarse-grained materials include the sand and gravel (or larger) soil particles. |
| Coated Piling | Steel sheet piling that is given a protective coating of coal tar epoxy or similar approved material. In certain environments, such surface treatment is specified in order to increase the effective life of piling. |
| Cobble | A rock fragment of 3 to 12 inches in size, usually rounded by weathering and abrasion. |
| Cobi Mandrel | A proprietary, segmented steel mandrel designed to be pneumatically expanded inside a thin corrugated shell to hold it while driving. |
| Coefficient of Restitution (e) | Nondimensional coefficient of cushion materials which accounts for the energy absorbing characteristics of the material. The value of "e" lies between 1 and 0. |
| Cofferdam | A structure which is built to exclude earth and water from an area in order that work may be performed there under reasonably dry conditions. A cofferdam does not have to be entirely watertight to be successful. It may be cheapter to permit some flow into the working area; water is then removed with pumps. See Cellular Cofferdam, Crib. |
| Cohesion | The bonding or attraction between particles of fine-grained soil that enhances shear strength and is independent of effective pressure. |
| Cohesionless Soil | A soil, sand, that when unconfined has little or no strength when air-dried and that has little or no cohesion when submerged. |
| Coil Bolt | Concrete formwork hardware consisting of two threaded inserts welded to ends of a small diameter steel rods. Bolts are inserted through the forms and threaded into the ends. This allows adjustment of the forms for vafious widths of concrete placements. |
| Column | A vertical shaft of many shapes designed to support the structure above. |
| Column Cap | Horizontal concrete beam that ties several concrete columns together, such as in bridge construction. |
| Column Clamp | Two perforated steel angles, approximately 36" long, that are hinged with a steel pin at one end to form an L-shape. Used in pairs and fastened with steel wedges to encompass a square column form. |
| Combustion Delay | The time between impact and compustion in an impact atomization diesel pile hammer. |
| Compacted Concrete Pile | A cast-in-place pile formed with an enlarged base. Dry concrete in the base is placed in small batches, which are compacted by heavy blows while plastic. See Enlarged Base, Franki Pile, Pedestal Pile. |
| Compaction | The process of inreasing the density or unit weight of a soil by preloading, rolling, tamping, vibrating, or other mechanical means. |
| Composite Pile | A pile made up of two or more types or sizes of piles joined together. The connection between the components is designed to transmit load and to prevent seperation during and after construction. See Spliced Pile. |
| Compound Batter Pile | 1. Pile driven at an angle in two directions from the principal line of the piles, normally expressed as a ratio of horizontal to vertical of the piles centerline (see Batter Pile) along with horizontal orientation angle from the principal line. 2. Pile driven on either for or aft batter and combined with side batter. Also called Skew Batter. |
| Compression bounce | The bounce of the ram, ususally on a diesel pile driver, that occurs after the hammer is shut off. Note: Rams will bounce up to 45 seconds after the fuel pump is shut off due to compression in the combustion chamber. Note: Diesel hammers have been known to re-start themselves if the fuel pump shut off rope is released to soon while there is still compression bounce. When shutting down a diesel hammer be sure to hold the shut off rope until the ram stops bouncing from compression. |
| Compression Leads | Pile hammer leads designed to withstand compressive forces from pile extraction operations (i.e., as used in pulling sand drains or mandrels). |
| Compression Web | A member connecting the top and the bottom chords in tension. |
| Compressive Stroke | Distance traveled by diesel hammer ram compresing cylinder gas. Measured from bottom of air intake port to point of impact. |
| Computer Wave Equation Program | A computer program used to solve the wave equation as applied to pile driving and speciifally to attempt to predict the optimum hammer size and pile length to acquire a desired ultimate bearing value of a pile. See WEAP, TTI and Diesel I Program. |
| Concrete Batching | Measuring the dry materials for a concrete mix (usually by weight) to control the quality of the mix. |
| Conical Point | A cast or fabricated steel drive shoe for pipe pile to help with easier driving, improved penetration, and prevent damage to the pile. |
| Constant Rate of Penetration | See CRP |
| Construction Point | Surface where two successive placements of concrete meet across which a bond is maintained between the placements. Reinforcement may or may not be interrupted. |
| Contact Sheeting | A propriety means of attaching horizontal timber lagging to the face of steel soldier piles as excavation proceeds. |
| Continuous Flight Auger | A pneumatic, electric or hydraulic drilling machine to which is connected a string of helical augers and a cutting head, used to bore holes in the earth, into which a pile section or tieback is set or concrete is cast-in-place. |
| Convertible Diesel Pile Hammer | A diesel hammer which can be opreted either open-end (single-acting) or closed-end (double-acting). |
| Cookie Cutter | A steel caisson with a circular base floated nto position like a huge barge and sunk all the way to bedrock to make a base for a bridge pier. |
| Coolie Hook | An elongated quick opening, shackle or clevis for handling sheet pile during setting. The pin is placed in a sheet pile handling hole and is released after the pile reaches grade. |
| Corbel | A block placed on top of piling at a cap joint. A projecting beam acting as a cantilever supporting another beam. |
| Core | A soil or rock sample removed by drilling. |
| Cored Pile | A pile formed by removing earth prior to pile installation. |
| Coring | Continuation of a soil boring into rock; a core may be recovered for examination and testing. See Dry Sampling. |
| Corner | A fabricated piling shape, either a bent shape or an assembly of piling, plates and angles, used as a means of changing the wall direction laterally. |
| Corner | Fender pile around the corner of a dock. |
| Corral | A pile supported enclosure in deep water used to position a caisson as it is being sunk. |
| cpm | Cycles per minute -- A measure of frequency. |
| Cradle, Hammer | A structure which slides on the rails of pile driver leads and carries the hammer forward of the lead rails. |
| Crane Boom | Spare beam or truss projecting from a crane to support a load. |
| Creosoted Pile | A timber pile impregnated with coal tar creosote to minimize deterioration. |
| Crew, Pile | The on-site personnel who will physically install piling on a project, including the crane crew, as applicable. Also called Dockbuilders, Bridgemen, or Pile Bucks. |
| Crib | A structure built of round or square timbers, or reinforced precast concrete members, laid in courses with the pockets filled with riprap or rubble. |
| Cross Bracing | Bracing constructed at right angles to the main axis and used as sway bracing. |
| Cross Head | See Head Block. |
| Crowd | 1. Downward thrust of kelly bar or auger caused by mechanical reactions against the weight of the boring rig. It is used when boring becomes difficult in hard formations. 2. Lateral thrust to hold a pile in position when it tends to drift. |
| CRP | Constant Rate of Penetration -- Load test accomplished by applying a load to the pile in such a manner that the pile top (head) experiences a constant rate of displacement and at short time intervals the force and displacement are recorded, from which a force displacement curve may be plotted; a definition of failure may be developed from this. Typical displacement rates range from 0.010 to 0.020 inches per minute. See MLT. |
| Cuneiform Pile | A tapered or step-tapered pile. |
| Curtain Wall | A non-load bearing wall. Also see Cut-Off Wall. |
| Cushion | See Pile Cushion. |
| Cushion Blocks | Blocks, stack or coils of material such as wood, plastic, compressed paper, aluminum, rope, etc. which are placed in drive cap under a pile hammer to receive and absorb a portion of the impact blow. Same as Cap Material, Dolly. |
| Cut Off | The excess portion of a pile above cut-off elevation. |
| Cut-Off Elevation | The elevation of the top of the pile as shown on the contract drawing. |
| Cut-Off Wall | A structure constructed, underground, to impede the flow of water as: 1. under stream beds in arid regions to extend to the surface to form a reservior; 2. under earth dams to prevent trickles from developing into dangerous channels; 3. under concrete dams to prevent underscour; 4. under earth or concrete levees. May be made of steel sheet piling, concrete (sometimes termied) puddled clay, injected grout or other material. Also called Curtain Wall. |
| Cutting Shoe | Additional metal placed as an inside or outside cast steel ring or welded plate at the bottom of an open-end pile or caisson to strengthen the tip. |
| Cylinder Lift | 1. The point at which the cylinder of a double-acting air or diesel pile hammer begins to lift or "float." 2. The point at which the force of fliud in the hammer overcomes the weight of the hammer casing cylinder. |
| Cylinder Pile | Circular pile constructed of concrete or steel. |
