郑万高铁小三峡隧道溶洞综合处理技术

Comprehensive Treatment Techniques for Karst Caves in Xiaosanxia Tunnel of Zhengzhou-Wanzhou High-Speed Railway

为解决隧道施工遇溶洞、岩溶管道、暗河等不良地质造成的突泥涌水、坍塌等问题,保证隧道施工及运营安全,通过工程技术人员对溶洞揭示情况、地质评价等情况进行综合分析,采用梁板跨越+外封内排+支护加强措施,介绍采用箱梁结构跨越溶洞与排水设计综合治理技术,并以郑万铁路小三峡隧道岩溶处理为工程实例。现场实践结果表明:1)采用梁跨结构,可跨越岩溶裂隙及溶洞破坏区段,提供稳固基础;2)采用地表河道铺砌措施及在隧道内溶洞区域设置排水通道,可有效减小地表水下渗;3)设计排水通道,起到溶洞水引排作用,排除隧底高水压积水,致使隧道轨面上拱风险。

To solve the problems of mud and water gushing and tunnel collapse caused by unfavorable geologies such as karst cave,karst pipeline,and underground river during tunnel construction,and ensure the safety of tunnel construction and operation,comprehensive countermeasures of beam plate crossing,sealing out of tunnel and drainage in tunnel,and support strengthening are adopted on the basis of kast cave conditions revealed and geological evaluation results.The box beam structure is adopted to cross karst cave,and drainage facilities are introduced by taking the karst treatment of Xiaosanxia tunnel of Zhengzhou-Wanzhou high-speed railway as an example.The field practical results show the following.(1)The beam span structure is feasible in karst fissure and karst cave damage section,which can provide a solid foundation.(2)The surface river paving measures and the drainage channel laid in the karst cave area of the tunnel can effectively reduce the surface water infiltration.(3)The drainage channel is designed to drain the high-pressure water in tunnel bottom,thus reducing the rail uplift risk of tunnel.