Technical Lecture on “Single Piles vs. Pile Groups Lateral Response under Static, Cyclic and Dynamic Loading” By Prof. A. Boominathan,Indian Institute of Technology Madras at IISc, Bangalore on July 5th 2013
The lecture was conducted in the Department of Civil Engineering, IISc. The lecture was attended by 30+ students and faculty of IISc and delegates from Industry.
Prof. Boominathan has explained the possible modes of lateral loads coming on the pile supported structures and drew his objectives of the present study. He considered the effect of various soil¬pile parameters and loading characteristics on the lateral response of single piles and pile groups embedded in clay. Prof. Boominathan explained that the study has a two-pronged approach.
In the first, laboratory 1 g model tests have been conducted on model single piles and pile groups in clay under three types of lateral loading conditions: static, cyclic and dynamic. The effects of various parameters such as spacing between piles, number of piles and configuration, embedment length and loading characteristics on load deflection and bending behavior of pile groups were investigated. Based on the experimental results, the p-y curves were developed and p-multipliers were evaluated for static and cyclic loading.
Numerical analyses were carried out by p-y curve approach using L PILE and GROUP software with inbuilt and experimentally evaluated p-multipliers for static and cyclic loading. The non-dimensional charts proposed in the study based on the model single piles and pile groups test results along with the field data of single pile tests were used to predict the behavior of pile groups in the field. In the case of dynamic experiments, the pile group impedance and interaction factors were evaluated considering pile-soil-pile interaction.
In the second, field lateral dynamic load tests were conducted at two different petrochemical complex sites in India and the measured dynamic constants of the soil-pile system. A three-dimensional finite element analysis was performed using ABAQUS to predict the nonlinear response of the soil-pile system under dynamic lateral loads. He explained that the finite element analysis was able to predict well the dynamic lateral response of pile for soft as well as stiff soil sites.