Driving Sheet Pile Walls
There are several ways of driving sheet pile walls into position; threading into pre-cut trenches, pressed, impact-driven and vibratory driven.
Threading sheet pile walls into pre-cut trenches is a suitable technique for use on most soils. After a trench has been excavated or holes drilled in the ground, they are filled with a suspension and sheet piles can be driven in up to their full depth.
Pressing sheet pile walls is a process that can be used if there are noise and vibration limitations due to the construction taking place in residential areas or near to existing buildings. The sheet piles are driven into the ground by hydraulic pressure. The pressing plant can be supported by a crane, guided by a leader or be supported by heads already in position.
Impact driven sheet pile walls can be positioned in the ground using either slow or rapid-action systems. Drop hammers and diesel hammers are slow-action, with between 24 and 32 blows per minutes and are used in cohesive soils. These hammers allow the pore water pressure to disperse between blows. Rapid-action hammers give between 100 and 400 blows per minute at a lighter driving weight than slow-action hammers.
Vibratory sheet pile driving is derived from harmonic excitation of the sheet pile, causing the restructuring of the soil along with decreasing the friction between the soil and sheet pile. Harmonic excitation is produced by eccentric weights in the vibrator.