Numerical Study of Tapered Pile Subjected to Cyclic Loading

The serviceability limit state is assured when the deflection resulting due to external load is within the specified limit. The deflection of a pile subjected to cyclic load can be reduced by replacing a regular pile with a tapered pile. A tapered pile is one in which cross section varies uniformly along the length. This study aims to analyse the behaviour of tapered piles in cohesionless soil subjected to cyclic loading. The study has been carried out in PLAXIS 3D. The tapered pile has been analysed by considering three broad parameters, which are: (1) loading conditions, (2) material properties, and (3) pile configuration. The pile has been subjected to one-way cyclic load in loading conditions and two-way cyclic load applied laterally. Soil properties have been varied by considering different relative densities of 60, 65, and 86%. Pile material consisting of steel and aluminium is taken into account. Pile configuration consists of cylindrical and tapered sections based on an equivalent volume approach. From the analysis, it has been found that a fully tapered pile has undergone less deflection than a regular pile. For one-way cyclic load having a frequency of 0.3 Hz, which proved to be critical, fully tapered pile undergone a deflection of 0.21 m which is comparatively lesser than the deflection obtained for regular pile, which is 0.25 m for a maximum load of 960 kN in soil having a relative density of 86%. Based on results from the analysis, it is concluded that tapered piles made up of steel embedded in dense soil experienced less deflection.