邻近地铁车站基坑开挖位移传递规律数值模拟

Numerical simulation of displacement transfer law of excavation adjacent metro station

上海地铁8号线人民广场站是个平行换乘车站,车站基坑紧邻地铁1号线人民广场站开挖。监测数据说明,随着基坑开挖,地铁车站背向基坑倾斜。通过有限差分法数值模拟,得到了邻近大刚度地铁车站的基坑开挖位移场的位移传递规律,并对其规律进行了分析,结果表明,大刚度地铁车站的存在对基坑开挖的位移场具有很大的影响:(1)对基坑变形的遮拦作用,从而减小了支护结构的变形;(2)隔断了坑周土层的位移传递路径,使得土体位移场发生变化,促使地下建筑物背向基坑方向倾斜。

People Square Station of Shanghai Metro No.8 is a parallel transfer station, of which excavation is adjacent to People Square Station of Metro No.1. Monitoring data indicate that the constructed station inclines reversely during adjacent excavation. Through FDM numerical simulation, displacement transfer behavior of excavation is analyzed; and displacement transfer law of excavation adjacent large stiftness underground building, is analyzed. The results show that a large stiffness underground building makes a great difference of displacement that： （1） block effect, which results to minish the displacement of retaining structure; （2） cutting off the path of soil displacement transfer, which changes soil＇s displacement and brings on building＇s inclination reverse to pit.