Effect of Stress Level of Surrounding Soil on Bored Pile Capacity in Sand


This study deals with assessing the effect of stress level on bearing capacityfactor , distribution of shear stresses at soil-pile interface along pile shaft, andpresence of critical depth concept for bored piles axially loaded in compression andembedded in dense sand. These investigations are made using finite element methodwith the employment of a wide range of stresses by using piles with dimensionsstarting from laboratory dimensions and goes towards field dimensions withembedment ratio range from (15-40). The soil and the interface behavior ismodeled using Duncan-Chang hyperbolic soil model with empirical equationsaccount for reduction of angle of internal friction ø with increasing in stress level.Bored pile is modeled as a linear elastic material. The results showed a dramaticdecrease in bearing capacity factor as length of pile increase. It was also foundthat the embedment ratio has a significant effect in increasing bearing capacityfactor , and the distribution of shear stresses at soil-pile interface is not linear anddoes not tend to take a constant value beyond a certain depth of pile nor decreasesafter a certain depth along pile shaft. The fallacy of critical depth also noticed anddiscussed in this paper.