深基坑支护结构力学与变形特性研究

Research on Structural Mechanics and Deformation Characteristics of Deep Foundation Pit Support

文中对基坑支护桩的力学特性和变形规律做了研究,通过在支护桩与冠梁安装土压力盒与应力计监测基坑支护结构应力变化、侧向位移以及地表沉降。结果表明:角点土压力强度随开挖深度变大呈先增大后减小,弯矩随开挖深度增加而增加;基坑段中部土压力强度随开挖深度先快速减小再增大,弯矩随开挖深度增加先增加后减小。锚索轴力随时间变化一直维持在一个稳定状态,中间锚索轴力大于两边。基坑边长越大,支护桩顶侧向位移越大,且当测点与基坑边缘距离0.75倍的开挖深度时,地表沉降达到最大值。

The mechanical characteristics and deformation law of the foundation pit supporting pile are studied, and the pressure change and lateral displacement and surface settlement of the foundation pit are monitored by installing the soil pressure box and stress gauge in the supporting pile and crown beam. The results show that the pressure strength of the soil in the middle part of the excavation section decreases rapidly and then increases with the excavation depth, and the bending moment increases with the excavation depth. The axial force is maintained in a stable state with time, and the intermediate axial force is greater than both sides. The larger the edge length of the foundation pit, the larger the lateral displacement of the support pile top, and when the excavation depth between the measuring point and the foundation pit edge, the surface subsidence reaches the maximum value.