基坑排桩对建筑抗震性的影响分析

以往对建筑抗震性影响因素的研究仅限于施工材料、技术手段等外部条件,忽略了基坑土体安全系数、基坑状态对建筑抗震性的影响,一定程度上削弱了建筑的抗震性能。本文从基坑排桩角度对建筑抗震性的影响展开分析,通过有限元强度折减法获取土体的安全系数与基坑状态的判断标准,在该标准下基于土体安全系数采用有限元强度折减法计算公式,获取各个土层计算参数。基于该参数使用ABAQUS有限元软件构建基坑排桩有限元分析模型(土体和桩体分别采用莫尔-库仑弹塑性模型和二维弹性模型)。实验采用所提分析方法,从基坑排桩排距、刚度两方面对建筑抗震性能进行分析。实验结果表明,当基坑排桩排距进行适当取值时,建筑抗震性越好;双排桩的刚度越大,建筑抗震性越好,且随着刚度的增加建筑抗震性能趋于平稳。

Influence of Foundation Pit Pile Rows on theSeismic Performance of Buildings

Previous studies on the factors influencing the seismic performance of buildings are confined to external conditions such as construction materials and technical methods. The influence of the safety factor of foundation soils and foundation pit conditions is often neglected, and this weakens the seismic performance of buildings. Therefore, in this study, the influence of foundation pit pile rows on the seismic performance of buildings is analyzed. Through the finite element strength reduction method, the safety factor of soil and the judging standards of the foundation pit condition were obtained, which helped to obtain the calculation parameter of each soil layer. Based on these parameters and the ABAQUS finite element software, the Mohr-Coulomb elasto-plastic soil model and a two-dimensional elastic pile model were adopted to establish a finite element analysis model of pile rows in a foundation pit. An experimental analysis method was used to analyze the seismic performance of a building from the aspects of row spacing and stiffness of the foundation pit. The experimental results show that if the foundation pit pile row spacing is properly selected, the seismic performance of the building would be effective. The greater the stiffness of the double-row piles, the better the seismic performance of the building, which tended to be stable with the increase of piles stiffness.