桥梁半边桩基础数值模拟分析及研究

Numerical simulation analysis and study on bridge's double-type pile foundation(a half of total piles are end-bearing type,another half are friction type)

采用变形法及有限元法对半边桩基础的受力特点进行了分析计算。通过对比各影响因素变化对半边桩基础受力的影响,可知基底摩擦系数及基岩弹性模量对半边桩基础受力变化影响较小,基础接触面的长度直接影响基础受力,接触面占基底面积比重越小基础受力越不利,因此半边桩基础设计时应将基础置于尽可能多的基岩上。有限元法采用非线性接触单元模拟基础接触面,考虑了各构件空间受力及变形的相互影响,通过对比分析可知有限元法的模拟计算是可行的,但其中的某些参数的选取还需大量工程实例的验证。

This paper analyzed and calculated the stress characteristics of half pile foundation by using deformation method and FEM.Comparing the force of half pile foundation with impact factors changes,this paper induced that the substrate friction coefficient and bedrock elastic modulus has little effect on the stress of half pile foundation,the length of the basic contact surface directly affects the basic force,and the basic force is negative when contact surface accounts for a small proportion of the basic area,which means the design of half pile foundation should make the bedrock as much as possible the basis.FEM simulated the basic contact surface by using the nonlinear contact element,which considered the mutual influence of each component space force and deformation.This paper concluded that FEM simulation method is feasible by the contrast analysis,but some parameters of which should be selected by a large number of engineering practice.