基坑支护结构计算方法的比较分析

Comparison and Analysis on Calculation Method for Retaining Structure for Foundation Pit

对于基坑支护结构的计算方法,目前较流行的是按照增量法的计算原理,采用简化的平面弹性抗力法计算,而普遍认为总量法计算值偏小。本文进一步探讨了总量法与增量法的计算模式原理。同时利用有限元软件分别构建了基于两种计算方法的有限元模型。通过对实际算例的计算,证实了在荷载施加正确的前提下,两种计算方法计算结果是一致的,且总量法更具优势。在此基础上,本文还对现行规范建议的三维空间计算方法与传统的平面计算方法进行了对比。从对比结果得出,距离支撑较远的支护桩的位移宜利用空间计算方法计算,以及冠梁及腰梁的尺寸对于增加支撑对支护桩的作用、改善支护桩变形来说,基本不起作用。

For the calculation method of retaining structure of foundation pit,the simplified method of plane elastic resistance is widely used according to the calculation principle of incremental method.This paper discusses the calculation model of total amount method and incremental method,and builds two models using the finite element software.According to the calculation results confirming the correct premise in the applied load,calculation results of two kinds of calculation methods are consistent,and the total method has more advantages.On this basis,this paper also compares the three-dimensional space calculation method proposed in the current code with the traditional plane calculation method.From the comparison results,it is concluded that the displacement of the retaining piles far away from the support should be calculated by space calculation method,and the size of the crown beam and waist beam has little effect on increasing the support effect on the retaining piles and improving the deformation of the retaining piles.