Piles and Pile Driving Equipment

Flashcards related to piles and pile driving equipment including definitions of terms, classifications of piles, timber piles, concrete piles, steel piles,composite piles, sheet piles and pile driving hammers.

Anchor Pile

A pile connected to a structure by one or more ties to furnish lateral support or to resist uplift.

Butt of a Pile

The larger end of a tapered pile; usually the upper end of a driven pile.

Cushion

Material inserted between the ram of a pile hammer and the driving cap to provide a uniform distribution of impact forces.

Cutoff

The prescribed elevation at which the top of a driven pile is cut; also the portion of pile removed after driving.

Downdrag

Negative friction of soil gripping a pile in settling soils, adding load to the installed pile.

Driving cap or helmet

A steel cap placed over the pile butt to prevent damage during driving, formed to accept a specific-shaped pile and its cushion.

Embedment

The length of pile from the ground surface (or cutoff) to the tip of the pile.

Overdriving

Driving a pile in a manner that damages the pile material, often due to continued hammering after refusal.

Penetration

Downward axial movement of the pile per hammer blow. Gross penetration includes rebound, net penetration does not.

Pile bent

Two or more piles driven in a group and fastened together by a cap or bracing.

Pile-driving shoe

A metal shoe placed on the pile tip to prevent damage and improve driving penetration.

Pile tip

The lower end of a pile, usually the smaller end for timber piles.

Soldier pile

An H or wide flange member driven at intervals into which horizontal lagging is placed to support excavation walls.

Tension pile

A pile designed to resist uplift.

Sheet Pile

Used primarily to create a rigid barrier for earth and water, for cutoff walls, cofferdams, bulkheads, and trenching.

Load bearing Pile

Can be made of Timber, Concrete, Steel or Composite materials. Used to transfer structural loads to the ground.

Treated Timber Piles

Timber piles treated with preservatives like salt or creosote to reduce decay and fight marine borers, especially when exposed to fluctuating water tables.

Concrete Piles

Piles that may be precast or cast-in-place, often prestressed or post tensioned and come in square, cylindrical, or octagonal shapes.

Steel Piles

Suitable for foundations requiring great depths, with high load-carrying capacity despite being more costly than concrete piles.

Composite Piles

Piles developed for special situations, combining materials like concrete and steel to optimize strength and resistance to deterioration.

Drop Hammers

A heavy metal weight lifted by a hoist line and released to fall onto the top of the pile

Single-Acting Hammers

A hammer with a freely falling weight, called a "ram," that is lifted by steam or compressed air

Double-Acting Hammers

Hammers where the striking ram (piston) is driven by compressed air or steam when both rising and falling.

Differential-Acting Hammers

Modified single-acting hammer in that the air or steam pressure used to lift the ram is not exhausted at the end of the upward stroke but is valved over the piston to accelerate the ram on the downstroke.

Diesel Hammers

A self-contained driving unit that does not require an external source of energy such as an air compressor or steam boiler.

Hydraulic Impact Hammers

Hammers reported to have an efficiency of 90% or better in delivering energy to the pile using hydraulic pressure.

Vibratory Drivers

Pile driver effective when the piles are driven into water-saturated noncohesive soils.