Pile Tip

The bottom end of a pile. Also called Foot of a Pile.

Pile, Cast-In-Place Concrete

See Cast-in-place Pile.

Pile, Timber

A tree trunk, usually debarked, driven into the ground. It may be pressure impregnated with creosote, pentaclorophenol, or chromated copper arsenate or ammoniacal copper arsenate.

Piling Contractor

The contractor, frequently a subcontractor, who specializes in installing piles.

Pipe Lead

Lead with main member of a pipe, to which a guide is attached for the hammer to slide on. Also called Monkey Stick, Spud Lead, European Lead or Pogo Stick.

Pipe Pile

See Steel Pipe Pile.

Piping

See blowing.

Piston

The part of the falling weight in a power pile hammer which is fitted with piston rings. See Ram.

Pitching the Pile

Positioning the pile in the leads for driving. See Lofting.

Plasticity

Term applicable to fine-grained cohesive soils (such as clays) with the ability to flow or be remolded without raveling or breaking apart. See Atterberg Limits.

Plug

The soil inside a pipe pile driven open-end.

Plumb Pile

A vertical Pile.

Pogo Stick

See Pile Lead.

Point of Fixity

See Depth of Fixity.

Pore Pressure

Water pressure developed in the voids of a soil mass. Excess pore pressure refers to pressure greater than the normal hydrostatic pressure expected as a result of position below the water table.

Positive Batter

See Fore Batter.

Posttensioning

A method of prestressing a concrete member in which cables or bars are placed in ducts through the concrete member. When the concrete reaches a specified strength, the tendons are tensioned by jacking against the member and then anchored to it. See Pretensioning.

Power Pack

A primve mover composed of an engine and generator hydraulic pump or compressor to provide electricity, hydraulic power or air to portable construction equipment such as a vibratory extractor or auger.

Practical Refusal

See Refusal.

Preaugering, Preboring or Predrilling

1. Boring through obstructions or materials too dense to penetrate with the planned pile type. This is commonly done for displacement piles in stiff clays where heave may occur.
2. Exploratory drilling to below utility lines to locate and minimize damage to unknown facilities.

Precast Pile

A concrete pile either reinforced or prestressed which is manufactured in a construction yard or at the site, and having been properly cured, is handled and driven like a steel or timber pile.

Precast Segmental Pile

A precast pile manufactured in lengths which enable the pile to be extended on site relatively quickly which a mechanical splice. See Bruns Pile, Pile Splicer.

Pre-Excavation

1. Advance excavation of a general site.
2. Removal by augering of soil that may heave.
3. Removal of soil by driving and cleaning out an open-end pipe.

Prefiring

See Dieseling.

Preignition

See Dieseling.

Pressure Grouting

See Grouting, Foundation.

Pressure Head

See Head.

Pressure Injected Footing

See Enlarged Base.

Pressure Meter

A device that can be lowered into a bore hole and expanded to determine the lateral resistance of the soil.

Pressure-Treated Pile

Round or sawn timber used as a pile, which has been pressure impregnated with a chemical preservative, e.g., creosote, pentachlorophenll, or ammoniacal copper arsenate or chromated copper arsenate.

Prestressed Pile

A precast concrete pile which is prestressed or posttensioned to reduce or eliminate cracking caused by tensile stresses to which piles are subjected during transportation, driving and in service.

Prestressing

Compressing a concrete member with tensioned cables or bars running through it to make it lighter for its strength and to counteract handling stresses.

Pretensioning

A method of prestressing a concrete member in which cables or rods are jacked against and then anchored to abutments in a form before the concrete is poured. When the concrete member has cured to specified strength, the tendons are detached from their anchorages and relieved of their stress. Restrained from shortening by bond with the concrete, the tendons compress the concrete member.

Primary Drive Cap

A drive cap that requires an adapter for different shapes of piles. It is used only with an adapter.

Production Pile

Pile which is part of a specified pile foundation, as opposed to a preliminary test pile.

Production, PIles

The number of piles which can be installed in a defined period of time (i.e., piles driven per 8 hour day).

Protector

A protective end reinforcement for steel sheet piling.

Pruyn Point

Trade name for a protective cast-steel pile point for H-pile.

psi, psf

Pounds per square inch (foot), the English unit of measure of pressure.

Puddling

A technique for achieving an uncontrolled degree of compaction of granular fill by saturating the soil after it is dumped into the excavation.

Pull Out Resistance

See Uplift Capacity.