Contiguous Piled Walls are used where the groundwater table is below the desired excavation level and can be installed using rotary bored or CFA techniques. They’re normally the fastest and most efficient piled wall option.
Technique
The wall consists of bored piles typically installed at centres 150mm greater than their diameter. Retained soil between the piles is exposed during excavation, and a spray concrete application with reinforced mesh can be applied as a lining to secure the exposed soil, and resist groundwater pressures for both temporary and permanent retained wall solutions.
Piles are installed, in a sequence determined by boring conditions. The wall is not watertight and measures may be required to prevent wash-out of ‘fines’ between the piles, e.g. shotcrete or gunite applications. Each pile is reinforced with a steel cage designed to resist bending moments and shear. Pile diameters of 350-1200mm are offered, retaining up to 15 metres.
