Analyzing the dynamic behavior of bored pile foundations in liquefiable soils using the finite difference method

Abstract

In sandy saturated soils which are at the risk of  earthquake, one of the most dangerous phenolmenon for structures is liquefaction . In order to prevent this phenolmenon and protect structures , pile foundation can be used. So we have to analyze the liquefaction effects on dynamic behavior of these foundation. In the present study , we use two- dimensional finite difference software for numerical analysis of concrete pile , with regard to nonlinear model of  liquefible  soil. In the following research the parametric study is focused on the effective parameters on the behavior of pile such as pile diameter and thickness of  liquefible  layer. Finally the scale and quality of each parameters influence on the seismic response of pile has been studied. Results are presented with increasing the thickness of liquefible  layer exceeds value of lateral displacement of pile head and this increase will be more piles with less diameters. Also if the thickness of the liquefying soil layer is much, increasing the diameter helps us to reduce lateral displacement. It is found for free- head piles, irrespective of the thickness of the liquefying soil layer, the maximum bending moment is developed at the interface between the liquefying soil layer and non liquefying soil layer.