长江漫滩富水砂层深基坑开挖变形控制

Deformation Control during Excavation of Deep Foundation Pits in Water-rich Sand Layer of the Yangtze River Floodplain

为了探究长江漫滩富水砂层地铁车站基坑开挖变形控制的影响因素,以南京地铁某车站基坑为例,通过应用有限元软件对基坑开挖过程进行模拟分析,研究地铁车站基坑开挖过程中基坑周围地表及地连墙支护结构的位移.根据实际地层参数模拟结果可知:随着基坑的开挖,主动土压力增大,竖向位移先增大后减小,在距离基坑位置远端,随着开挖深度越大,基坑周围地表沉降越大;基坑地连墙支护结构位移曲线呈现明显的波动和增长趋势,对比不同开挖阶段的位移曲线可知,地连墙的水平位移随着施工过程推进呈现逐渐增大的趋势.

In order to explore the influencing factors of deformation control during excavation of deep foundation pits in water-rich sand layer of the Yangtze River floodplain,taking a subway station foundation pit in Nanjing as an example,finite element software was applied to simulate and analyze the excavation process of the foundation pit.The displacement of the surrounding ground surface and the retaining wall support structure during the excavation process of the subway station foundation pit was studied.According to the simulation results based on actual geological parameters,it can be seen that as the excavation of the foundation pit,the active soil pressure increases,and the vertical displacement first increases and then decreases.At the far end of the position from the foundation pit,as the excavation depth increases,the surface settlement around the foundation pit increases.The displacement curve of the foundation pit retaining wall structure shows a more obvious fluctuation and growth trend.By comparing the displacement curves under different working conditions,we can find that as the construction process progresses,the horizontal displacement of the retaining wall gradually increases.