温度对地铁深基坑支护结构的影响分析

Effect of Temperature on Supporting Structure of Metro Deep Foundation Pit

目的研究地铁深基坑工程中支护结构受温度的影响规律,分析造成影响的各种因素,为类似地铁深基坑工程支护结构的保护提供指导。方法以有限元分析软件ABAQUS为基础,结合沈阳地铁十号线北大营站地铁工程,建立有限元模型,将分析数据与实测数据对比,以此验证有限元模型,并通过模型分析确定温度对基坑支护结构的影响因素。结果温度对支撑轴力的影响较大,支撑轴力随着温度升高而增大,反之减小;温度变化会使钢支撑产生热胀冷缩,导致围护结构水平位移的增加,对基坑整体和基坑周围环境造成不利影响。结论温度变化会使钢支撑产生热胀冷缩,地连墙发生朝向基坑内方向的移动趋势,通过改变钢支撑和围护结构的力学性质减小温度对支护结构的影响,提高施工的安全性。

The influence of temperature on the supporting structure of subway deep foundation pit and its various factors that cause the influence are analyzed,so as to provide reliable guidance for the protection of supporting structure in similar subway deep foundation pit engineering.Based on the finite element analysis software ABAQUS,taken the subway project of Beidaying station of Shenyang Metro Line 10 as research object,the finite element model is established.The model is verified by simulation data and the measured data.The influence factors of temperature on supporting structure of the foundation pit are determined through the model simulation.The results show that the temperature has a great influence on the support axial force,and the force increases with the increase of temperature and decreases on the contrary;the change of temperature will cause thermal expansion and cold contraction of the steel support,resulting in the increase of horizontal displacement of the retaining structure,which has adverse effects on the whole foundation pit and the surrounding environment of the foundation pit.And meantime the diaphragm wall will move toward the direction of foundation pit.By changing the mechanical properties of steel support and retaining structure,the influence of temperature on the supporting structure can be reduced,and to improve the safety of construction.