结合经济性优化的地下连续墙支护结构鲁棒性设计

Robustness design of underground diaphragm wall supporting structure combined with economic optimization

在未考虑岩土力学参数的变异系数及变异系数标准差的情况下,岩土工程确定性设计与可靠度设计存在一定的风险。为克服岩土力学参数的非确定性对地下连续墙支护结构设计的影响,并优化设计方法的经济性,针对隆起破坏、墙体倾覆破坏、支护结构侧移破坏三类破坏模式,提出了适用于地下连续墙支护结构的鲁棒性设计方法。通过杭州地铁文新站工程案例,分析各种破坏模式下几何参数与鲁棒性设计的关系,并通过设计流程确定地下连续墙支护结构设计的几何参数最优解。研究结果表明:增加地下连续墙深度、加固土厚度均可提高隆起破坏模式的鲁棒性;增加地下连续墙深度可显著提高墙体倾覆破坏模式下的鲁棒性;增加地下连续墙厚度、加固土厚度可显著提高支护侧移破坏模式下的鲁棒性。该设计方法可获得同时满足安全性、鲁棒性、经济性的几何参数最优解。

Without considering the coefficient of variation and the standard deviation of the COV of geomechanical parameters,there are certain risks in the deterministic design and reliability design of geotechnical projects.In order to overcome the influence of uncertainty of geomechanical parameters on the design of underground diaphragm wall supporting structure and optimize the economy of the design method,the author proposes a robust design method for the design of underground diaphragm wall supporting structure under three failure modes:uplift failure,wall overturn failure and sidesway failure of supporting structure.Through the engineering case of Wenxin Station,Hangzhou Metro,the relationship between geometric parameters under various failure modes and robustness design is analyzed,and the optimal solution of geometric parameters in the design of underground diaphragm wall supporting structure is determined through the design.The results show that increasing the depth of underground diaphragm wall and the thickness of reinforced soil can improve the robustness under uplift failure.Increasing the depth of underground diaphragm wall can significantly improve the robustness under wall overturn failure.Increasing the thickness of underground diaphragm wall and reinforced soil can significantly improve the robustness under sidesway failure of supporting structure.This design method can derive the optimal solution of geometric parameters satisfying security,robustness and economy simultaneously.