地铁换乘车站基坑支撑轴力监测与数值模拟

Monitoring and numerical simulation of axial forces of struts for foundation pit of a metro transfer station

以某地铁换乘车站基坑为研究背景,研究基坑开挖过程中支撑轴力随基坑开挖时间的变化规律。建立三维有限元模型对地铁车站深基坑开挖过程进行模拟计算,将获得的支撑轴力计算值与实测值进行了对比分析。结果表明:第四道钢筋混凝土支撑的支撑轴力最大,第五道和第六道钢支撑的设计偏于保守,支撑的拆除会对其相邻支撑产生很大影响。支撑轴力的计算值小于实测值,但其发展变化的趋势几乎一致。三维有限元模型能够较好的模拟异形基坑的开挖过程,可以为优化设计和施工提供有益的参考。

Based on the foundation pit project of a metro transfer station, the changing laws of the axial forces of struts with the excavation time are studied. A three-dimensional finite element model is established to numerically simulate the foundation pit of the metro station. The FEM and in-situ monitoring results of axial forces of struts are compared. The results show that the axial forces of the fourth concrete strut are the maximum, and the design values of the fifth and the sixth steel struts are conservative. Besides, the removal of a strut has a notable influence on its adjacent struts. The calculated results are less than the in-situ monitoring ones, but the trend of their changing laws is almost uniform. The three-dimensional finite element model can simulate the excavation process of abnormal foundation pits, and it can be used to provide reference for their design and construction.