NONLINEAR DYNAMIC ANALYSIS OF LATERALLY LOADED PILE

Abstract

Pile foundations are generally preferred when heavy structural loads have to be transferred through veak soils to firm strata. Pile foundation may be subjected to variety of loading conditions, such as static, cyclic or dynamic loads. The design of laterally loaded pile involves consideration of usually large ratio of lateral to vertical loads, particularly in areas subjected to severe storms. Analysis of pile foundation for vertical load follows conventional procedures; the lateral load analysis poses a more complex problem. The design become more complex when the load is dynamic in nature as the dynamic response is found to be more than the static response for same equivalent force. in the present study a parametric analysis is conducted to study the effect of pile dimension and soil modulus on the nonlinear dynamic response of pile subjected to lateral load at the pile head. The study is conducted on soil-pile model of different pile diameter, pile length and soil modulus, and results are compared to get the effect. The soil-pile system is modeled using Finite element method. The programming is done in MA'I'LAB. 'lime history analysis of model is done for varying non-dimensional frequency of load and the results are compared to get the non-dimensional frequency at which pile head displacement is maximum in each case. Maximum possible bending moment and soil-pile interacting forces for the dynamic excitation of the pile is also compared. When results are compared with the linear response, it is observed that non-dimensional frequency is reduced in nonlinear response on account of reduction in the soil stiffness due to yielding. Nonlinear response curve shows high amplitude as compared to linear response curve.