某地铁车站深大基坑支护结构受力分析

Analysis of Deformation and Internal Force of Retaining and Protecting Structure of Deep Foundation Pit

深大基坑开挖施工过程中,围护桩和支撑的变形与内力监测,是保障基坑和支护结构稳定性的重要措施之一.以某地铁车站路基深大基坑为例,采用ANSYS有限元软件建立二维模型,分析基坑支护结构在开挖过程中内力变化和位移的关系,并与实测数据进行了对比.结果表明:较其他三道钢支撑而言,钢筋混凝土支撑的轴力最大.基坑两侧围护桩剪力和弯矩分布基本上呈对称分布.由于基坑两侧围护桩长度和背后土层分布的不同,基坑东、西两侧桩体水平位移变化趋势及最大值所处位置有较大差异.

During the excavation of deep foundation pit,monitoring of the deformation and internalforce of supporting pile and brace is one of the important measures to guarantee the stability offoundation pit and supporting structure. The deep foundation pit of a subway station is taken asthe example to analyze the relationship between the internal force and displacement in the processof excavation of foundation pit supporting structure by establishing two -dimensional model usingANSYS finite element software. The comparative analysis between the monitoring data andthe numerical result indicates that the axial force of the reinforced concrete brace is the largestcompared with the other three steel braces. The shear force and the bending moment of the pileshow the symmetrical distribution on both sides of the foundation pit. There are significantdifferences between the trend of the horizontal displacement and the location of the maximum valueon both sides on account of the difference of the pile length and soil thickness distribution.