Pile Driver Machine: The Complete Guide

The pile driver machine is composed of a pile hammer, pile frame, and auxiliary equipment. The pile hammer is attached between two parallel vertical guide rods (commonly known as gantry) at the front of the pile frame and is hoisted with a lifting hook. The pile frame is a steel structure tower frame, and a hoist is provided at the rear of it for lifting piles and pile hammers. There is a guide frame composed of two guide rods in front of the pile frame, which is used to control the direction of pile driving so that the pile can accurately penetrate into the ground according to the designed orientation. The basic technical parameters of the pile driver are the impact part weight, impact kinetic energy, and impact frequency. Pile hammers can be divided into drop hammers, steam hammers, diesel hammers, hydraulic hammers, etc. according to the power source of the movement.

Working Principle

• Steam hammer pile driver: Use high-pressure steam to lift the hammer head up, and then impact the pile head downwards by the hammer head’s own weight, so that the pile sinks into the ground.
• Vibratory hammer pile driver: use the mechanical vibration force of the pile hammer to sink the pile into the ground, suitable for carrying small prefabricated concrete piles, steel sheet piles, etc.
• Static pile driver: The pile is pressed into the soil under the action of continuous static pressure by using the pressure generated by the mechanical winch or the hydraulic system, and it is used for various prefabricated piles with general bearing capacity.

Application

When the bearing capacity of the foundation is insufficient and it is not suitable for direct excavation (such as quicksand, silt, swamp, etc.), piling is used. The purpose is: to strengthen the soil; to transfer the load, so as to ensure that the superstructure will not be deformed or damaged due to uneven settlement of the foundation.

• The shape of the pile: wooden pile, steel pile, cement pile, reinforced concrete pile, etc.
• Stress forms of piles: end-bearing piles, friction piles, hybrid piles.
• Piling depth: enough to withstand the pressure of the superstructure without deformation.
• According to the design service life of the building: (permanent, short-term, temporary) generally hit the design bearing layer.

Classification

Pile hammers can be divided into drop hammer pile drivers, pneumatic hammer pile drivers, diesel hammer pile drivers, hydraulic hammer pile drivers, etc. according to the power source of the movement.

Pile drivers can be divided into screw pile drivers and hammer pile drivers according to their piling methods.

Selection Guide

The type, standard, power and number of pile drivers to be invested must be selected according to the following conditions：

• Geological conditions: The primary basis is the geological exploration report, and the condition of the bearing layer is mainly considered.
• Construction ability: consider the qualification scale and construction ability of the construction unit.
• The type and geometry of the pile determined by the planning drawings include pile length, diameter, length into the bearing layer, number of piles in the pile cap, single pile bearing capacity, pile plane and the total number of piles.

Maintenance

All mechanisms, moving parts, and hydraulic systems of new equipment should be refueled or lubricated according to regulations before working.

• The hoist, column guide rail, slewing mechanism, slewing support, diagonal brace adjustment mechanism, support sprocket, guide wheel, and drive wheel bracket should be inspected regularly and lubricated on a regular basis.
• Wire and cable joints, where they are prone to collision and friction, should be covered or protected with protective tubes.
• When working, carefully check whether the power head, or the flange bolts of the vibrating hammer, and the bolts and nuts of the operating mechanism are loose.
• When working, you should pay attention to whether the lower ball seat of the lead screw is moving up and down every day. If there is a series of movement, you should stop working immediately, remove the end cover of the ball seat extending under the beam, put pressure on the diagonal brace, and tighten the nut at the lower end. And lock it tightly, and weld the nut firmly with electric welding if necessary. When the temperature drops below zero in winter, check whether there is water in the protruding beam, and remove the water in time to prevent the nut from being loosened by freezing.
• When the diagonal strut rotates, pay attention to observe whether there is any swing phenomenon. If there is any swing, replace the guiding copper sleeve or copper nut in the diagonal strut in time.
• The oil tank, oil pump, and control valve of the hydraulic system should be kept clean.
• The pulley blocks, bearings and other rotating parts of the pile frame are equipped with grease nipples, which should be filled with calcium-based lubricating grease on time.
• The track chain should be cleaned every working day to ensure that the track is clean and running normally.
• The slips of the power head, the nylon sleeve of the pulley, and the copper sleeve of the main winch should be replaced in time.
• Steel wire ropes should be inspected, maintained and used in accordance with relevant national standards.
• The supporting mechanism shall be used and maintained according to the requirements of the supporting manual.

Precautions

Safety precautions for pile drivers at work:

• When the pile driver is working, it must be commanded by a special person. Commanders and operators should check each other’s signals before working. Work closely together.
• At the beginning, an electric bell or other means should be used to send out a signal to inform the surrounding people to leave.
• The pile driver and the pile cap, the pile cap and the pipe column (or pile) plane should be flattened, the connecting bolts should be tightened, and the looseness should be checked frequently.
• The start of the pile driver should be accelerated from low gear to high gear step by step.
• When the pile driver is working, pay close attention to the current and voltage indications on the control panel. If abnormal noise or other abnormal conditions are found, stop the machine immediately for inspection.
• Always check the bearing temperature and whether the bearing cover screws are loose, and strictly check whether the eccentric iron block connecting screws are loose to prevent accidents.
• When sinking, it is strictly forbidden to stand around the pipe string (or pile).
• When the pile driver cooperates with water injection and mud suction to sink, it should contact the relevant personnel in advance and take care of each other during work.
• Workers must wear safety belts when connecting long pipes or piles and installing pile caps.
• During the sinking process, mechanical maintenance and maintenance work is strictly prohibited.

Troubleshooting

Causes and troubleshooting methods of common faults of pile drivers: