圆形深基坑环撑刚度计算分析及应用

Calculation Analysis and Application of Ring Brace Stiffness of Circular Deep Foundation Pit

通过圆形基坑实例,推导单个环形支撑的水平刚度系数,提出了圆环支撑刚度系数的简易计算公式,利用其解析解作为支护结构单元计算刚度输入的初始数据,并通过启明星BSC计算软件及迈达斯GTS-NX三维有限元软件计算出的位移和内力及基坑开挖后实测的位移和内力对环撑水平刚度进行反推,并与解析解对比。结果表明:解析解计算出的环撑水平刚度系数较反推计算结果偏大。根据对比分析,对环撑水平刚度系数计算公式进行了修正,修正结果能基本与反推结果吻合,可为今后类似圆形深基坑的设计、施工提供参考。

Through an example of a circular foundation pit,the horizontal stiffness coefficient of single annular support was deduced,and a simple calculation formula of stiffness coefficient of annular support was proposed.Its analytical solution was used as the initial data for calculating the stiffness of supporting structure element.Through the displacement and internal force calculated by BSC and Midas GTS-NX,combining with the measured displacement and internal force after foundation pit excavation,the horizontal stiffness of the ring brace was deduced and compared with the analytical solution.The results show that the horizontal stiffness coefficient calculated by the analytical solution is larger than that calculated by the inverse calculation.According to the comparative analysis,the calculation formula of the horizontal stiffness coefficient of the ring brace was modified.The modified results can basically coincide with the inverse calculation,which can provide guidance for the design and construction of similar circular deep foundation pit.