Bearing mechanism of rock-socketed piles with void beneath pile tips

Abstract

This paper investigates the bearing mechanism of rock-socketed piles (RSPs). The small-scale model tests and the theoretical analysis are performed to study the influence of the void beneath the pile tip at various distances (h) on the bearing capacity of the RSPs. The governing equation of pile-soil/rock system is proposed by the load transfer mechanism. The relationships between different factors are obtained based on the model test in the laboratory, including the top load (Pt)-top settlement (st) of pile, pile unit side friction (τ(z))-pile-soil relative displacement, τ(z)-pile–rock relative displacement and pile tip unit resistance (pb)-pile tip settlement (sb). The results show that τ(z) increases and pb decreases with the proximity of the void to the pile tip, thus in general decreasing the bearing capacity of the RSPs. The bearing mechanism of the RSPs with the void beneath the pile tip at h is analyzed, and the safety distance of the void beneath the pile tip is also determined. The results provide guidance for RSPs engineering in void areas.