How Vibratory Hammer Works

The vibratory hammer consists of two major components, gear case and suppressor.

The gear case contains eccentric weights, which rotate in a vertical plane to create vibration. The hydraulic motors mounted on the gear case drive the eccentric weights. The hydraulic motors and eccentric weights are connected to maintain proper synchronization. Only vertical vibration is created in the gear case, as the paired eccentrics cancel horizontal vibration.

The vibration created in the gear case is transmitted into the pile being driven (or extracted) by means of a hydraulic clamp attached to the bottom of the gear case.

A suppressor assembly is mounted to the top of the gear case to isolate vibration to the crane. The suppressor contains rubber elastomers, which dampen the vibration reaching the crane by 90% or more.

A hydraulic clamp, bolted to the bottom of the gear case, transmits vibration to the pile attached. The universal clamp contains two gripping jaws; one fixed and one moveable. A hydraulic cylinder operates the moveable jaw with different types of capacity to grip the pile. See ICE Clamp.

The vibratory hammer is powered by a power pack. Fixed displacement pumps and a Caterpillar diesel engine provide all the power required by the hydraulic motor and the clamps. ICE uses an open loop hydraulic system rather than closed loop hydraulic system. This system uses less mechanical and electrical components and provides better serviceability, less complexity and easier trouble shooting.

Vibratory Hammers and Soil Conditions

Vibratory driving occurs relatively easily in non-displacement piles such as sheet piling, H-beam, and open-end pile or caissons.

Granular soil (sand)

The vertical vibration in the pile disturbs or "liquefies" the soil and causes the soil particles to lose their frictional grip on the pile. The pile moves downward under its own weight, plus the weight of the vibratory hammer. Amplitude of at least 3mm is usually required to cause enough soil disturbances to achieve pile driving.

Cohesive soil (clay)

The vibration will shear the soil from pile adhesion and allow the pile to move downward. Amplitude of at least 5mm is usually required to cause enough relative movement to shear the soil away from the pile.

Pile Extraction

Vibratory hammer is usually very effective, as the soil under the pile tip that resists driving does not have to be moved.

Soil Compaction (granular soil)

Vibratory compaction works well as the soil disturbance due to vibration causes the soil particles to move into a denser configuration. Large amplitude results in a high soil strain level, a greater influence radius and higher degree of compaction.  ICE has forced lubrication models that are suitable for soil compaction work. ICE vibratory hammers with forced lubrication and cooling system allow long working hours and prevent overheating.

Underwater Applications

ICE vibratory hammer can also be adapted to work underwater with an additional underwater kit.