Bearing capacity of CHD piles compared to traditional piling techniques in sand

The paper introduces a piling system known as the Continuous Helical Displacement (CHD) pile. The pile has a number of advantages over current piling methods during installation, particularly when installed on brownfield sites. The method has been developed to achieve greater performance when installed in coarse grained soils when compared to conventional piling methods. In order to determine the origins of the improved performance, research is being carried out at the University of Dundee on the CHD piling technique. Model testing was used to compare the performance of simulated CHD, driven and auger bored piles. This work showed that the CHD has enhanced performance compared to bored piles and is more comparable to driven pile behaviour. The bearing capacity N-q factors were investigated and found to increase as the soil density decreases. This behaviour suggests the CHD pile improves the soil performance when installed in loose material.