兰州某地铁车站深基坑监测与数值模拟分析

依托兰州市地铁某车站基坑工程,对基坑施工过程中的桩顶水平和竖向位移、地表沉降、钢支撑轴力及地下水位进行了监测,并对监测数据进行了系统分析。监测结果分析表明,桩顶水平位移随着基坑的开挖由小变大逐渐趋于平稳,桩顶竖向位移随着开挖深度的增加而逐渐增加,在开挖的过程中钢支撑的轴力趋于稳定。最后借助有限元软对基坑开挖进行了数值模拟,并将模拟结果与监测结果进行了对比分析,结果表明,数值模拟和监测结果变化规律基本一致,证明了钻孔灌注桩联合钢管内支撑结构安全可行,保证和维护了基坑的稳定,为类似基坑的施工提供了有效可靠的参考资料。

Monitoring and numerical simulation of deep foundation pit of a subway station in Lanzhou

Based on the foundation pit of a subway station in Lanzhou, the horizontal and vertical displacements of pile top, surface settlement, axial force of steel supports and groundwater level of foundation pit during construction are monitored, and the monitoring data are analyzed. The monitoring results show that the horizontal displacement of pile top gradually changes from small to large and the vertical one of pile top increases with the increase of excavation depth, and the axial force of steel supports in the excavation process tends to be stable. Finally, the finite element software is used to simulate the excavation of the foundation pit. The simulated and monitoring results are compared. The results show that the numerical simulations and the monitoring results basically have the same variation rules. It is proved that the combined structure of steel tube bored pile and support is safe and feasible, and it ensures and maintains the stability of the foundation pit. This study may provide effective and reliable reference for the construction of similar foundation pits.