岩溶发育区毗邻地铁桩基施工技术研究

Research on Construction Technology of Pile Foundation Adjacent to Subway in Karst Developed Area

地铁运营对周围地层的稳定性要求较高,在毗邻地铁的岩溶区施工桩基础,既要确保桩基施工质量和安全,又要确保地铁变形稳定。对于常规的溶洞注浆预处理工艺,其高压浆液对土体的冲刷极易造成地铁地层过大变形,因此不能采用。本文结合工程实例,总结出一种全套筒全回旋钻孔,内嵌护筒穿过溶洞成桩的施工技术。研究结果表明,在岩溶强烈发育的地区,在地铁等对地层变形敏感的地下建构筑物毗邻区域内,施工桩基础采用此技术可以确保施工质量、安全,确保既有地下建构筑物安全、稳定,并具有较高的经济效益。

Subway operation requires high stability of surrounding strata,the construction of pile foundation in the karst area adjacent to the subway should not only ensure the quality and safety,but also ensure the stability of subway deformation.The conventional karst cave grouting pretreatment can not be used,because its high-pressure slurry is easy to cause excessive deformation of the subway stratum This article combines engineering examples and sunmarizesthe construction technology of full rotation full casing drilling,and embedding a pile casing through the karst cave to form a pile.The research results show that in the area where karst is strongly dev eloped and in the adjacent area of underground buildings and structures that are sensitive to stratum deformation,such as subway,this technology can ensure the construction quality and safety,ensure the safety and stability of existing undergound buildings and structures,and have higher economic benefits.