悬挂式深基坑地下连续墙支护数值模拟及工程优化

现场监测难以预测基坑和围护结构后期变形规律,为提前预判并规避基坑破坏风险,采用数值模拟方法预测基坑变形及围护结构工作状态。依托南京市和燕路过江通道八卦洲明挖段实际工程,针对悬挂式地下连续墙深基坑支护方式,动态模拟基坑开挖,研究地连墙墙体深层水平位移和墙体弯矩变化规律,对比监测数据验证模拟合理性。改变悬挂式地下连续墙厚度及埋深,发现地连墙厚度增大可减小深层水平位移,但对抗弯性能要求较大；增大墙体埋深可减小水平位移和墙体弯矩,但超过一定深度影响减小,通过寻求墙体厚度及埋深合理值,优化施工方案。

Numerical Simulation and Engineering Optimization Analysis of Diaphragm Wall for Cantilevered Deep Foundation Pit

It is difficult to predict the later deformation of foundation pit and retaining structure by field monitoring. In order to predict in advance and avoid the risk of foundation pit damage, numerical simulation method is used to predict the deformation of foundation pit and the working state of retaining structure. Based on the actual project of the Baguazhou open excavation section of the river crossing passage of Heyan Road in Nanjing, aiming at the supporting mode of deep foundation pit of cantilever diaphragm wall, the dynamic simulation of foundation pit excavation was carried out to study the variation law of deep horizontal displacement and bending moment of diaphragm wall, and the rationality of simulation was verified by comparing the monitoring data. By changing the thickness and buried depth of the cantilever diaphragm wall, it was found that the increase of the thickness of the diaphragm wall could reduce the horizontal displacement of the deep layer, but the requirement of bendingstrength was large; the increase of the buried depth could reduce the horizontal displacement and bending moment of the wall, but the influence was reduced if the buried depth is too deep. The construction scheme was optimized by seeking the reasonable value thickness and buried depth of the diaphragm wall.