Hydraulic Pile Hammer Glossary

Hydraulic Pile
Hammer Glossary

The BRUCE Hydraulic Vibro Hammer Standard Glossary of Terminology has specially been prepared with the object of unifying the various technical terms and expressions targeted for majority members of construction conductors on sites who are being involved with BRUCE Pile Hammer and Vibratory Hammer to be operated at the various different Vibro Hammer operation taking place through the world. We wish and aim with our continue efforts that this will be standard in the pile driving industries.
This type of Hammer operation has no Leader is used and normally is accomplished its pile driving work on offshore project.
The Hammer requires a lifting wire rope to lift it directly by a Crane due to the limitation of taking Cranes position when it is being apart from the land.
The Long Pile Skirt is generally used for marine and offshore pile driving job.
Cushions are used to protect both the hammer and the pile.
Cushions that protect the hammer are called hammer cushions or hammer cushions.
Cushions used to protect the pile are called pile cushions.
It is a recent days method to assess a piles Bearing Capacity by applying a dynamic load to the pile head while recording Acceleration and strain on the pile head that is also a high strain dynamic test which is applied during the pile operation.
When a Ram drops and strikes the top of the pile, a compressive stress wave travels down its shaft at a speed which is a function of the elastic modulus and mass density.
The impact induces a force and particle velocity at pile and is computed by multiplying the measured signals from a pair of strain transducers and modules and
accelerometers transmit data to a high strain dynamic testing system such as the Pile Driving Analyzer (PDA) for signal processing and the results.
A cushion consisting of a block of hardwood, plastic or other suitable material placed on top of the helmet to receive the blows of the hammer and to distribute it evenly over the surface of the helmet.
It has been developed through long years of pile driving experience and its kinds are various such as RC, PC and PHC Concrete Piles.

It normally can be divided into pre-case and cast in place concrete piles following the forming process.
It is formed and reinforced in a high quality controlled concrete piles shaping square, triangle, circle or octagonal type.
When the BRUCE Hammer approaches the Concrete Pile Driving, the working stress design method is calculated as 280, 340,and 540 kg for RC, PC and PHC Concrete Piles, respectively within the range of below 20 tons Hammer to select an optimum pile driving condition.
BRUCE defined this as a Practical Refusal of BRUCE Hammers in accordance with Warranty Policy on the Operating Manual that described as the Hammer doesn’t want to operate longer than 10 hours per day and get recess time for 30 minutes for system cooling when it continuously supposed to be operated for 2 hours of non-stop operation.
It is called as Steel Tube Pile or Tubular Pile by many workers on sites.
This pile is manufactured in seamless spirally welded or well lap-welded and is normally installed by top driving but in difficult ground conditions and also it can be installed by a combination of drill and drive.
Casing Piles driven by BRUCE Hammer for marine and offshore application Have usually large diameter and are therefore often driven as open-ended to resist lateral and uplift loading.
However the base resistance of open-ended piles can be low in loose to medium dense granular soils.
When the BRUCE Hammer approaches the Casing Pile Driving, the working stress design method is calculated as 2,400 kg within the range of below 20 tons Hammer to select an optimum pile driving condition
A driven (cast in situ) pile in which a light metal casing is driven into the ground with the help of a mandrel, and after the casing has reached the required depth,
the mandrel is withdrawn leaving the casing in position to be filled with concrete.
It is fabricated by BRUCE to wrap up the Drive Cap and to connect with a Pile Cap or a Long Pile Skirt either for onshore and offshore pile driving purposes which are a kind of auxiliary Pile Cap provided upon customers request.
There are a two Buffer Rings inserted on top of Cap Housing to absorb the shocks from rebound occurrence or other reasons.
The rebound of the hammer on hitting the pile.
Too much bounce is a sign of inefficient-driving as a large part of the energy is diverted from driving.
Bouncing will nearly always occur as pile is near its desired set but bouncing in the beginning is an indication that hammer is too light for the task