柔性桩沉降的随机特性

Random Characteristic of Flexible Pile

本文采用小波动方法结合剪切位移法,将土体弹性模量视为沿深度方向的一维随机场,推导出了柔性桩桩顶沉降响应方差上限的解析表达式。通过算例探讨了四种不同相关函数及相关距离对往身沉降及桩身应力响应方差的影响。得出了指数型相关函数较其它三种的计算值明显偏小;当竖向相关距离大于桩长时其变化对桩顶沉降响应方差影响不大的结论。

In this paper, by using the small fluctuation approximation with shear displacement method and the modeling soil modulus as one dimension random field, the explicit solution of upper limit of variance response of pile top settlement was derived. The effects of four different auto-correlation function and the correlation distance on response variance of pile settlement and stress were analyzed by typical example. It is concluded that the computing result of auto-correlation function of exponensial type is less than the three other types of function. When the vertical correlation distance is longer than the length of pile, it has small influence on the response variance of pile top settlement.