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 |
| Tack | 1. Term used to describe small weld used for temporary purpose. 2. Phrase used to describe the act of hitting sheet piles down with hairpin so they will have some penetration into the ground to stabilize whe wall as used in "tack the sheets." |
| Tag Line | A soft line used to control the load being raised by a crane from swinging aroung. |
| Tapette | See Caisson Hammer. |
| Taywood Sheet PIle Driver-Extractor | A heavey device with hydraulic rams attached to several individual sheet piles; rams are operated seperately to push or pull a sheet while others furnish reaction. |
| Tee Pile | Fabricated piece made up of a full and half piece of piling to form a single T-shape. In cellular construction, each cell will contain four tee piles that connect the main cells with the short arc walls. |
| Telescope Lead | A structure which holds a pime hammer in wider than hammer width box leads and permits extended driving by carrying the hammer beyond the bottom of the leads. Also called Hairpin, Pony Leads. |
| Template | A fabricated guide used to align the piling before driving. Circular templates may have one or more rings against which piles are set to form the circle of the cell. This can be almost any shape; square, rectangular, etc. Single walls are generally set against a beam as a guide. |
| Template, Pile | See Grid. |
| Tenon | The head of a timber pile after being cut or shouldered to accommodate splicer or other devices. |
| Tension Capacity | See Uplift Capacity. |
| Tension Pile | A pile designed to resist uplift. |
| Teredo | See Marine Borer. |
| Test Borings | See Soil Boring. |
| Test Loading | See Load Test. |
| Test Pile | 1. A pile driven to ascertain driving conditions and probable required lengths. 2. A pile on which a load test also may be made to determine its capacity and the carrying capacity of the soils. 3. A pile driven as a guide for efficient design of a pile foundation. See Indicator Pile. |
| Test Pit | A method of examining soil by excavating a pit to permit direct examination of the materials in place and its degree of compaction, as well as permit test loads directly on what will be the foundation soils. |
| Texas Quick Load Pile Test | Similar to constant Rate of Penetration Test. |
| Thimble | An oval shaped reinforcement around which the rope is bent when forming an eye. |
| Thin Wall Shell Pile | Corrugated shell or thin pipe, concrete filled, driven with aid of mandrel. See Swage Pile, Helical Shell. |
| Thread | See Lace. |
| Throttle Valve | A quick-acting valve mounted in the fluid line used to control the flow of fluid to a steam/air pile hammer. |
| Tie Beam | Concrete beam that connects and distibutes loads to pile caps or spread footings. |
| Tie Rod Legs | The forged extension of the tie rods in the hammers no. 2, 5, 6 and 7 which acts as a retainer for the anvil. |
| Tie Rods | The rods in all hammers, extending the entire length of the hammer, which hold the parts of the hammer together. |
| Tie-Back | A rod or cable grouted or fixed to an in-ground anchor to resist soil or other pressure on walls or structures. See Anchor Pile. |
| Till | Dense heterogeneous mixture of fine-grained and coarse-grained material of glacial origin and compaction. It often contains significant quantities of boulders and cobbles. See Glacial Till and Hardpan. |
| Tilt-Up Construction | Method of concrete consturction in which members are cast horizontally at a location close to their final position, and tilted in place after the forms are removed. |
| Timber Pile | A cut tree, usually debarked, and pressure treated with creosote or other preservative, usually driven small end down. Probably the earliest form of a pile. |
| Tip | See Pile Tip. |
| Tip Elevation | See Pile Penetration. |
| Tip Resistance | See End Resistance. |
| Top Block | See Anvil. |
| Top Head | See Head Block. |
| Top Man | See Pile Monkey and Trip. |
| Top Plate | See Anvil. |
| Towing Post/Sampson Post | A "T" shaped or cross shaped post mounted near the rear of a work boat or tugboat used to tie lines for towing barges, logs, etc. |
| TPT Pile | A proprietary precast concrete tip pile with then-shell shaft, driven with the aid of a mandrel. |
| Training Wall | A structure constructed along a river of loose mounds or heaps of rubble, with or without a surmounting masonry wall, timber, close timber piling, wood sheet piling, steel sheet piling or reinforced concrete to direct the flow of the river into a more favorable, fixed channel. |
| Tremie | 1. Placing concrete below water level through a pipe, the lower end of which is kept immersed in fresh concrete so that the rising concrete from the bottom displaces the water without washing out the cement content. 2. The hopper and drop pipe used to place the concrete underwater; this is now frequently done by pumping the concrete. |
| Trepan | A large heavy tool dropped on a line down a bore hold to advance the excavation in rock under water. |
| Trestle | 1. A temporary work bridge to provide access to work site and support equipment; frequently used in rivers for access to pier construction. 2. A timber, reinforced concrete steel structure, which is used to support a pile rig during driving. 3. A bridge, usually with short spans and light superstructure, supported directly on pile bents. |
| Triangular Lead | See European Lead. |
| Trip | 1. A block in the leads of a drop hammer causing the release of the weight at a predetermined height. 2. Mechanical device used in diesel hammer to both pick up the hammer and to start the hammer. Also called Trip Block or Tripping Device. |
| Truss Leads | Pile hammer lead fabricated with four main chords in a generally rectangular shape with the chords being connected by diagonal bracing. May have internal diagonals to form a tetrahedral design. The piile hammer is mounted in front of and rides on two of main chords. |
| TTI Program | Title of a computer wave equation program standing for Texas Transportation Institute and developed at Texas A & M University for the Federal Highway Administration. |
| Tube Pile | A steel pipe pile. |
| Turnbuckle | A coupling between two threaded rods in which one end has female left-handed threads and the other end has female right-handed threads. It is used to adjust the length of a cable, rod or brace. |
