Nonlinear investigation of laterally loaded piles in layered sand with a modified conical strain wedge model

This paper describes a modified conical strain wedge model for the nonlinear analysis of laterally loaded piles in layered sand. The modified conical strain wedge model can not only treat layered sand in the wedge, but also obtain a novel expression of subgrade reaction modulus related to soil strain by conducting the force balance analysis and introducing the Duncan-Chang model of the soil. Combing the pile-soil interaction expressions based on the modified conical strain wedge model and a finite difference model of a one-dimensional beam on a nonlinear elastic foundation, an iterative procedure for predicting the nonlinear response of laterally loaded piles is developed. The comparison with the measured results from full-scale field tests and laboratory model tests shows that the proposed method can much better predict the nonlinear response of laterally load piles than the existing analytical methods. The rationality and well applications of the proposed method are further demonstrated by discussing some key parameters and influencing factors.