岩溶区超大断面地铁车站暗挖工法比选与应用

Comparison and Application of Underground Excavation Methods for Super Large Section Subway Stations in Karst Areas

为研究超大断面车站暗挖施工安全性和技术经济性,依托贵阳地铁3号线贵医站暗挖工程,对双侧壁导坑法、拱柱暗挖法和双层叠合初支拱盖法3种超大断面暗挖工法进行了适用性分析,通过有限元模型对周边围岩位移和应力变化规律进行了模拟,并对其安全、技术经济性进行了分析评价,提出了主要施工控制要点。结果表明:双层叠合初支拱盖法对周边围岩影响较小,具有安全可靠、工期短、造价低的特点,在贵阳岩溶地区实用性比其余2种工法优势明显,可为类似地铁建设提供借鉴和指导。

In order to study the safety and technical economy of underground excavation construction of super large section subway station,based on the underground excavation engineering of Guiyang Metro Line 3,the applicability of three kinds of super large section underground excavation methods,including double side drift method,arch pillar underground excavation method and double-layer composite initial support arch cover method,are analyzed.The displacement and stress variation of surrounding rock are simulated by finite element model.The safety and technical economy are analyzed and evaluated.The main construction control points are put forward.The results show that the double-layer composite arch cover method has little influence on the surrounding rock.The characteristic of safety and reliability,short construction period and low cost make the double-layer composite arch cover method is superior to the other two methods in Guiyang karst area.It will provide reference and guidance for similar subway construction.