Numerical analysis of interfacial shear degradation effects on axial uplift bearing capacity of a tension pile

Abstract

The bearing capacity of tension piles involves complex interactions between the tension-pile with the neighboring sediments. A two-dimensional axisymmetric finite element model (FEM) is proposed and verified with the existing experimental results to simulate the uplift resistance of the pile under axial/vertical loading. With an updated contact-pair algorithm for modeling pile-soil interfacial behavior, the modeling for both the interfacial bonding and the sliding friction mechanisms is fulfilled in the present model, which is capable of simulating the shear degradation effects by the breakage treatment of the pile-soil bonding. The bearing capacity of tension piles in various sediments can be predicted efficiently. Numerical results indicate that, due to the interfacial bonding effect, the enhancement of the tension bearing capacity gets more obvious for higher cohesion strength of the sediments. The interfacial bonding degradation of is the main reason for the occurrence of “critical embedded length” phenomenon.