隐伏溶洞与地铁车站深基坑安全距离确定方法

Determination Method of Safety Distance between Subway Deep Foundation Pit and Karst Caves

针对喀斯特地区岩溶地层地铁车站深基坑工程安全施工的严重影响,本文基于突变理论,利用有限元方法,分析不同临近程度溶洞条件下基坑系统的能量势函数,通过判断其临界状态跃迁参数变化与溶洞塑性影响区发展规律,分析溶洞与基坑空间距离对基坑安全的影响,提出一种可量化邻近基坑的溶洞安全距离的评判方法。研究表明,该方法较对溶洞分布安全评判的传统精度更高,操作性更强,可对后续类似工程的施工部署与方案指定提供理论指导。

Aiming at the serious influence of karst stratum in karst area on safety construction of the subway deep foundation pit.,and based on mutation theory,the energy potential function of foundation pit suffering from karst caves with different distance was systematically analyzed by means of finite element method in this work.Through judging the change law of critical state transition parameters and the development of cavern plastic zone,the effects of karst caves on foundation pit were studied,and a method evaluating the safety distance of karst cave adjacent to foundation pit was proposed.The results show that the safety distance between the foundation pit and karst caves calculated by the method proposed in this work had a higher precision and simpler operations,which can provide theoretical guidance for the construction deployment and scheme designation of subsequent similar projects.