Vibratory Pile Hammer Product

Overview

A vibratory pile hammer is a hydraulically powered tool that vibrates piles, sheet piling, and caissons into the ground using centrifugal force rather than impact. Unlike impact hammers that deliver a sudden shock, the vibrator applies a continuous sinusoidal oscillation at 0–100 Hz, reducing ground resistance and allowing the pile to sink under its own weight. The vibrator is suspended from a mobile crane, clamped to the pile, and operated remotely by the pile driver crew.

The machine is ideal for cohesionless soils (sand and gravel) where liquefaction and vibration-induced particle rearrangement allow the pile to slide down. It is less effective in clay and rock, where impact is preferred.

How it works

The vibrator is a self-contained hydraulic system mounted on a frame. A main hydraulic pump, typically driven by the crane's hook block or a separate diesel engine on larger rigs, supplies pressurized oil to a variable-displacement Hydraulic Motor. The motor rotates an Eccentric Shaft at speeds from 0 to 3,000 rpm. The eccentric shaft has counterweights offset from its geometric center, so as it spins, the rotating weights generate a centrifugal force that oscillates vertically — this is the vibration.

The amplitude (pile movement) is controlled by the static moment of the eccentric weights, typically 500–2,500 kg·cm. The frequency is the shaft rpm divided by 60. At 1,500 rpm, the vibration is 25 Hz; at 3,000 rpm, 50 Hz. The Flow & Pressure Control Panel allow the operator to adjust the motor displacement via a Pendulum Operator Control, varying the pump's output and thus the shaft speed. Higher flow means faster eccentric rotation and higher frequency. The Proportional Flow Valve meters pump flow proportionally to the operator's command.

The Vibrator Head Assembly containing the eccentric shaft, Bearing Block, and Oil Bath Housing is mounted inside a Vibration Suppressor Housing housing. The suppressor is lined with Elastomer Liner, elastomer blocks that absorb vibration and reduce radiated noise by 90+ dB. Without the suppressor, the hammer would vibrate its own frame, the crane cable, and everything nearby into destruction.

The entire assembly is suspended from a crane by Crane Lifting Lugs forged onto the frame. Vibration isolation Isolation Pad pads are mounted between the vibrator frame and the crane hook, further decoupling vibration from the crane structure.

Pile Gripping Clamps, hydraulic or mechanical jaws, grip the pile tightly around its perimeter. The clamp force is 100–400 kN depending on pile diameter and type. As the hammer vibrates vertically, the pile oscillates up and down in synchrony, sliding downward through the soil. The operator watches the Frequency Indicator and Pressure Gauge, adjusting frequency and amplitude to match the soil. Sandy soils respond well to higher frequencies (80–100 Hz); stiffer soils may need lower frequencies (20–30 Hz) and higher amplitude.

Pile resistance is monitored by observing the system pressure — as the pile sinks faster, the motor load drops and pressure falls. If the pile stalls, pressure rises, and the operator reduces frequency to avoid overloading the eccentric bearings or damaging the pile. The hydraulic Pressure Relief Valve protects the system by venting excess flow at 210 bar.

The Hose & Cable Bundle carry high-pressure oil from the pump to the motor and return to the tank, with separate pilot lines controlling the proportional valve. All hoses are routed through armored sleeves and color-coded for quick identification on site.

Once the pile has been driven to the design depth, the operator reduces the vibrator to idle, the pile comes to rest in the compressed soil, and the Pile Gripping Clamps are released. The hammer is lifted by the crane for the next pile. A skilled pile-driving crew can drive 20–50 piles per day, depending on pile length and soil conditions.