Complete Guide of Sheet Pile Driving Methods and Equipment

Sheet Pile Driving Methods and Equipment Introduction

AGICO now supplies hot-rolled sheet piles to customers worldwide. We also have rich experience in sheet pile retaining wall projects. AGICO offers you the complete guide to 3 major pile-driving methods: hammering driving, vibratory hammer driving, and hydraulic pressing-in. Before piling construction, the appropriate driving technique, equipment, method, and parameters shall be determined based on the type and model of the hot-rolled steel sheet pile, driving depth, ground conditions, site constraints, surrounding environmental requirements, and local engineering experience. The characteristics of the 3 driving methods are as follows:

Impact Hammer Pile Driving Method

The impact hammer driving method offers high impact force, good maneuverability, and fast driving speed. However, the hammer must be suitable to prevent damage to the pile head. The hammering process generates noise and vibration, so it is not suitable for near residential areas, schools, hospitals, or other specific zones. Types of hammer machines include diesel, hydraulic, drop, and pneumatic hammers.

The driving depth achievable by the hammering method depends on various factors such as ground conditions, the type of hot-rolled steel sheet pile, and driving technique.

Based on experience of our project, the maximum driving depths for certain specifications are shown in the table below.

Construction Precautions

1. When driving by hammering, the hammer shall be selected according to geological conditions, sheet pile model, pile layout, penetration depth, site conditions, surrounding environmental requirements, and local engineering experience.
2. A pile cap shall be used, matching the hammer and aligned with the pile axis. The gap between the cap and the sheet pile shall be 5–10 mm.
3. In hard clay, a heavy hammer with low drop height shall be used.
4. In dense sandy soil, a light hammer with rapid blows shall be used.
5. The penetration depth per hammer blow shall be strictly controlled, preferably not exceeding 300–500 mm.
6. Driving shall be suspended if sudden changes in penetration resistance, sudden tilt or displacement of the pile, severe rebound, or damage to the pile top or body occurs. The cause shall be analyzed and appropriate measures taken.

Vibratory Hammer Sheet Pile Driving

A vibratory hammer generates vertical vibrations transmitted to the hot-rolled steel sheet pile, causing it to vibrate up and down and penetrate the soil. This method offers high efficiency and facilitates both driving and extraction.

Electric vibratory hammers draw high instantaneous current and require large electrical power supply. Hydraulic vibratory hammers need a dedicated hydraulic unit. In hard soils where a vibratory hammer struggles to drive, it can be combined with a high-pressure water jetting device.

Maximum driving depths for certain specifications are shown in the table below.

Construction Precautions

Key points for vibratory driving of hot-rolled steel sheet piles:

• Layout and alignment: Based on the driving plan, surveyors first establish the axis of the sheet piles. Guide piles may be set at intervals, and a string line used as a guide to control the axis during driving.
• After clamping the pile with the vibratory hammer and lifting it into position, initial driving shall be performed. The verticality of the sheet pile shall be checked using a theodolite or plumb bob before formal vibratory driving. The first pile driven (as a guide) must be positioned and driven straight to avoid affecting subsequent piles.
• Driving sequence: The first 20 piles shall be driven in a left-right alternating (skip) pattern outward to both sides. After forming an integral pile wall, driving may continue continuously to one side to prevent tilting.

Hydraulic Press-in Method

In soft ground conditions, the method uses the reaction force from already driven sheet piles, with a hydraulic mechanism clamping the middle of the pile body to press it into the soil. The hydraulic press-in rig is compact, suitable for under-beam construction, allows ultra-close-range work, and can walk on top of the driven sheet piles. However, special cranes are required for lifting the piles. In hard ground, an auger drill combined with the pile press can be used to pre-drill holes and then press the sheet pile hydraulically. The use of a sleeve increases stiffness during penetration, making pile twisting unlikely.

This method achieves low noise and low vibration, ensures high vertical accuracy, and thus provides high driving quality. It is applicable to a wide range of soil types.

Maximum driving depths for certain specifications are shown in the table below.

Tips for Hot-Rolled Steel Sheet Piles Driving

In specialized construction of hot-rolled steel sheet piles, the effects of noise, vibration, and soil displacement on the surrounding environment during driving and extraction shall be comprehensively considered. Appropriate construction techniques and driving equipment shall be selected, and necessary environmental protection measures shall be taken to keep impacts within allowable limits.

How To Reduce Noise and Vibration Impacts

The hammering method, due to its noise and vibration issues, shall not be used in urban projects. When environmental protection requirements around the site are strict, the vibration or static pressing method shall be choosed. When using the vibration method, a low-noise, low-vibration vibratory hammer shall be selected. When strict control of vibration and noise is required, the static pressing method shall be adopted.

When using the vibration or hammering method to reduce noise and vibration impacts, appropriate vibratory hammer equipment shall be selected based on geological conditions, and the frequency and amplitude shall be dynamically adjusted to avoid resonance, which could cause severe soil vibration around the sheet pile. Resonance-free hydraulic vibratory hammers shall be your option.

Auxiliary Method for Hard Earth Conditions – Predrilling And Water Jetting

Additionally, the first 20 piles shall be driven in a left-right alternating (skip) pattern outward to both sides; after forming a short sheet pile wall, driving may continue continuously to one side. In hard soil layers with high driving resistance, auxiliary measures such as pre-drilling or high-pressure water jetting may be used to reduce resistance, significantly improving efficiency and also lowering driving noise and vibration.

When encountering hard clay layers, dense sand layers, gravelly soil, rock layers, or other hard earth areas, auxiliary measures such as water jetting or pre-drilling may be used to help pile installation. In expansive soil areas, when using water jetting to assist driving, a trial driving shall be conducted prior to production driving to determine the optimal water consumption. If water tightness is not required, a large-jaw interlocking connection may also be used.

When using pre-drilling as an auxiliary measure, the diameter, number, spacing, and depth of pre-drilled holes shall be determined based on the sheet pile cross-section type, dimensions, and soil properties. The pre-drilled hole diameter shall not exceed the sheet pile width (diameter may be 50–100 mm smaller than the sheet pile width), and the depth shall be 2–3 m less than the pile length. During pre-drilling, soil carry-out shall be minimized, and driving shall follow immediately after drilling.

When using the water jetting auxiliary method, an air compressor shall be provided on site to generate high-pressure water. The number and position of water pipes, water pressure, etc., shall be determined based on the sheet pile cross-section type, dimensions, and soil properties. Water consumption shall be minimized through reasonable process parameter settings.

The arrangement of the high-pressure water jetting device is shown in the picture below.

When To Stop The Sheet Piling Driving Process

If sensitive buildings (structures) or public areas exist near the sheet pile construction site, measures such as attaching sound-absorbing materials to the pile body, installing noise barriers, vibration isolation zones, or vibration isolation trenches may be adopted to keep noise and vibration within permissible limits. The width of a vibration isolation trench may be 0.5–1.0 m, and the depth shall be such that the slope can stand unsupported depending on soil conditions. If any of the following abnormal situations occur during driving, driving shall be suspended, the cause analyzed, and countermeasures taken:

• Hammering method: sudden change in penetration resistance, sudden tilt or displacement of pile, severe rebound, damage to pile top or body, etc.
• Vibration method: buckling deformation of pile top, damage to interlocks, etc.
• Static pressing method: abnormal pressure gauge readings, unusual noises, slipping of clamping device, excessive uplift displacement of reaction piles, etc.