基坑开挖对邻近桩基的影响及数值分析

Influence of Foundation Pit Excavation on Adjacent Pile Foundation and Its Numerical Analysis

深基坑开挖时的土体侧向移动使邻近桩基产生侧向位移和附加应力及弯矩,甚至可能使上部建筑物功能失效,因此深基坑开挖时土体侧向移动对邻近桩基的不利影响分析是有必要的。本文采用有限元软件MIDAS/GTS建立基坑开挖三维实体模型,分析基坑开挖对邻近桥桩的影响;根据相关计算结果,采用MIDAS/CIVIL建模验算邻近桩基的极限承载力及桩身裂缝宽度。结合监测数据可知,数值模拟结果与实测结果相近且在安全控制范围,基坑开挖对邻近桩基的影响及数值分析对施工预测有一定的指导意义。

The lateral movement of soil during deep excavation could causes lateral displacement, additional stress and bending moment of adjacent pile foundation, and may even invalidate the function of the upper building. There-fore, the adverse effects analysis of lateral movement of the soil during deep foundation pit excavationon adjacent pile foundations is necessary. The finite element software MIDAS/GTS are used to establish the 3D solid model of foundation pit excavation, so as to analyze the influence of foundation pit excavation on adjacent bridge piles. According to the relevant calculation results, MIDAS/CIVIL modeling is used to check the ultimate bearing capacity and crack width inpile body of adjacent pile foundation. Combined with the monitoring data, the numerical simulation results are close to the measured results, and both of them are within the scope of safety control. The numerical analysison influence of foundation pit excavation on adjacent pile foundation have certain guiding significance for construction prediction.