基于动态监测的地铁深基坑变形机理分析

Deformation Mechanism Analysis of the Subway Deep Foundation Pit Based on Dynamic Monitoring

利用信息化手段对武汉某地铁深基坑变形和支撑轴力展开动态监测,结合监测成果,重点分析了冠梁水平位移、坑外地表沉降以及钢支撑轴力的变化。对基坑变形和内力变化的原因及机理进行了探讨。分析表明,墙后土体压力及钢支撑轴力之间相互作用是导致基坑发生变形的主要原因。此外,基坑前期变形、内力监测均呈现较为明显的变化,随着支护体系的完善,各监测值逐渐趋于稳定,说明基坑支护和维护体系能够有效地控制基坑变形,可以保证地铁深基坑的安全施工。

This paper used information technology to launch dynamic monitoring into deformation and steel strut axial force of a subway deep foundation pit in Wuhan. Combining with the monitoring results, the paper emphatically analyzed the changes of crown beam horizontal displacement, surface settlement of pit outside and steel strut axial forces, and discussed the reason and mechanism of deformation and internal force changes. The results show that the interaction between earth pressure and the steel strut axial force is the main reason of foundation pit deformation. In addition, both the prophase deformation of the foundation pit and internal force monitoring present a signii cant change. With the improvement of the supporting system, the monitoring values gradually stabilized, this indicates foundation pit supporting and maintenance system can ef ectively control deformation of foundation pit, and ensure safety construction of the subway deep foundation pit.