便桥荷载作用下深基坑地下连续墙变形特性分析

为了研究便桥荷载作用下深基坑地下连续墙变形特性,以深圳市地铁6号线科学馆站超深基坑的上跨便桥段支护工程为依托,采用有限差分程序FLAC^3D结合现场监测情况对便桥荷载作用下超深基坑地下连续墙的墙顶沉降、墙顶水平位移和地表沉降等变形特征进行了分析,通过实测与模拟变形对比分析,验证了数值模型的可靠性,在此基础上对便桥荷载作用下的地下连续墙墙底失稳机理进行了探讨,根据极限承载力理论得出了相应稳定性验算公式,并对影响地下连续墙变形的主要因素进行了分析。研究表明:影响地下连续墙变形的主要因素为土层性质、便桥荷载和地下连续墙嵌固深度;墙底土体与墙侧土体比较,前者的强度和刚度对地下连续墙的变形影响更大;便桥荷载作用下地下连续墙容易产生墙底失稳,应对其墙底稳定性进行验算。

Analysis of Deformation Characteristics of Diaphragm Wall in Deep Foundation Pit under Load of Temporary Bridge

To analyze the deformation characteristics of diaphragm wall under the load of temporary bridge, the deformation laws of the settlement, horizontal displacement of the top of diaphragm walls and the surface settlement around the ultra-deep foundation pit under the load of temporary bridge were analyzed using the finite difference program FLAC^3D based on the supporting engineering of the temporary bridge situated on the ultra-deep foundation pit of the Science Museum Station in Shenzhen Metro Line 6. The reliability of the numerical model was verified by comparing the simulated data with the actual monitoring data, and the mechanism of bottom instability of the underground continuous wall under the load of the temporary bridge was discussed. According to the theory of ultimate bearing capacity, the corresponding stability checking formula was obtained and the main factors affecting the deformation of underground continuous wall were explored. The results showed that the main factors affecting the deformation of diaphragm wall were soil layer property, temporary bridge load and the embedded depth of continuous wall. Compared to the soil at the side of the wall, the soil at the bottom of the wall has a greater influence on the deformation of the underground continuous wall. The bottom of the underground continuous wall is prone to instability under the load of the temporary bridge, and the stability of the wall bottom should be checked.