Research On Deformation Rule Of Deep Excavation With Top-down Construction Method In Shenzhen-metro Laojie Street Station

As the process of urbanization speeding up in China, metro accesses to a period which metro is large-scaled and fast built. To be functional requirements, extra-large, extra-deep pits are built. Because the projects nature of station soil is bad it causes unprecedented problems on pit-support designs and construction technics in east coastal cities, like Shenzhen. Supporting structure of pits like that, deformation and motion rules of circumjacent soil are badly need to be studied.In this paper, it based on practice of Laojie Street 3# Shenzhen metro station and the main body of inter-change, top-down construction method,foundation pit is 27.5m deep,8300m2 big.Study concerns on the stability of supporting construction, mostly studies on distributing disciplinarians of earth pressures caused during the digging foundation pit process and displacement, stress, strain, by means of academic analysis, numerical simulation, etc.. It takes the way of real-time monitoring on the process of excavating Laojie Street metro station foundation pits. According to the design requirements, project situation, study content, monitoring-measure stresses on the supporting structure of foundation pit in west. Reasons of warps between design and practice are summed up and analyzed by dealing with the real-time monitoring data from project of foundation pit and contrasting results of theatrical calculating and numerical simulation.As all above, this paper studies on deformation rule of foundation pit, analyzes the stability of supporting construction, predicts the degree of construction security, and feedbacks conclusions to practice optimizing the project, which achieves some practical results.