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.
|R||Symbol for pile capacity in tons. Example: 2R is a term meaning twice design capacity.|
|Rabbit||See Pile Monkey.|
|Racking Hammer||Severe bouncing of the casing of a power pile hammer during driving operations.|
|Rail Pile||Usually three recycled railroad rails with edges of their bases welded together and the heads out, driven as a unit.|
|Railroad Pile Driver||A pile driver mounted on a crane with railroad undercarriage for convenient transportation on the rails and operation on track.|
|Raker Pile||See Batter Pile.|
|Ram||The moving or driving part of an air, steam, diesel or drop pile hammer which delivers an impact blow to an anvil and to the pile. Also called Piston.|
|Ram Point||The part of the ram that comes closest to the impact surface of the pile. Sometimes a separate unit of the ram.|
|Range Pile||A pile serving as a guide for locating piles or other structures or for marine surveying or dredging.|
|Rat Hole||See Doodle Hole.|
|Rated Speed||The specified operation speed for a pile hammer in blows per minute.|
|Raymond Step-Tapered Pile||Trade name for a spirally corrugated light gauge shell made in 4 to 16 ft sections of increasing diameter to form a step-tapered pile.|
|Reaction Pile||See Anchor Pile.|
|Reamer||A tool attached to the drilling bucket or auger to cut or enlarge the bell at the base of a drilled shaft or caisson.|
|Rebar Cage||See Cage.|
|Rebound||1. Amount of upward movement of the head of a pile following a blow from the hammer by reason of the elastic properties of the pile as well as of the soils into which it is driven.
2. The upward movement of t he head of the pile on removal of a static load.
3. The initial upward movement of a pile hammer ram after a blow on a pile.
|Rectangular Cofferdam||A temporary wood or steel sheet piling, braced, single-walled, rectangular shaped enclosure installed to permit construction of a foundation below ground or water level.|
|Reeve||To pass the end of a rope through any opening as you do when making up a block and tackle.|
|Refusal||The condition reached when a pile or soil sampler being driven by a hammer has negligible penetration per blow (as when the point of the pile reaches an impenetrable bottom such as rock), or when the effective energy of the hammer blow is no longer sufficient to cause penetration. For piling this is often empirically taken as 8 to 12 blows per inch. Same as Practical Refusal, Pile Refusal.|
|Reinforced Concrete||Concrete with embedded reinforcing bars or fibrous material to provide additional tensile strength.|
|Reinforced Pile||A regular piling shape that is strengthened with plates welded to the flanges. By this means, section moduli and resisting moments can be increased considerably.|
|Reinforcing Steel||Steel bars with deformed little projecting edges to insure that they will not pull out of the concrete and that the bond between the steel and concrete will be perfect. It comes in round bars in smaller sizes and square bars in larger sizes. It is bent or straight according to where the added strength is needed.|
|Relative Density||Term applied to granular soil masses to indicate a relative state of compaction compared to the loosest and most dense conditions possible.|
|Relaxation||The characteristic of a pile to show a decreased static capacity after driving due to pore water pressure changes, soil remolding, stress redistributions in the soil and others.|
|Residual Soil||Soil formed in situ by rock decay and left as a residue after the leaching out of more soluble products.|
|Resisitance||The sum total of all the forces that oppose the penetration of a pile under a hammer b low or a static force.|
|Retaining Wall||A structure constructed to withstand the lateral pressure of earth behind it and its own weight imposed on the soil beneath it.|
|Retarder||A mixture added to concrete to delay or slow the stiffening of the concrete.|
|Reverse Circulation||A counter-flow method of circulating drilling fluid and spoil in a drill hole. In the direct circulation method drilling fluid is pumped down a hollow drill pipe, around the drill bit, and back to the surface in the annular space around the drill pipe and the suttings are carried to the surface by the flow. In the reverse circulation or counter-flow system, drilling fluid is introduced into the annular space around the drill pipe by a high capacity low head pump. Also applies to cleaning steam boiler tubes.|
|Reverse Head||A means of stabilizing a bore hole by maintaining a head of water in the bore above the level of the surrounding water table.|
|Rider Cap||See Drive Cap.|
|Rig||See Pile Drive.|
|Ringing||Rings of steel up to an inch thick and three to four inches wide are driven over the shaped head of a wooden pile using a top maul to drive the ring in place.|
|Rip Rap||Large pieces of hard rock placed on a slope to minimize wave and wash erosion.|
|Rock||The ultimate soils material upon which to base a foundation. The compressive strength of good stone is greatly in the excess of masonry. Limestones may be subject to caving as a result of eroding ground waters.|
|Rock Anchors||High tensile bars or cables grouted into holes drilled into rock.|
|Rock Point||Pile point protection specifically designed to develop a toe hold on rock, or to improve penetration into the boulder infested soils.|
|Rock Socket||That portion of the pile bore which penetrates into a hard formation beneath less competent overburden. See Drilled-in-Caisson.|
|Rope Suspended Lead||See Offshore Lead.|
|Rotary Boring||A method of boring using rotary (as opposed to percussive) means of excavation.|
|Rotary Drill Rig||1. A drilling machine powered hydraulically, pneumatically, electrically, or mechanically to bore explatory holes or for installation of piles, caissons, or insitu piles. The equipment may utilize a continuous flight auger or a rotary table and Kelly bar with various attachments and tools to perform the work. See Continuous Flight Auger and Kelly Bar.
2. A Wet Rotary Drill Rig uses high-pressure water to open a hole for installation of a mandrel-driven pile.
|Rub Rail||Rubber or other material attached to the side of boats, docks, etc. to protect and cushion the boat, dock, etc. when they come in contact while docking.|