遵毕高速尖山岩溶隧道坍塌数值模拟与施工控制

以遵义至毕节高速公路段尖山Ⅰ号隧道Zk1745＋061岩溶坍塌为工程实例开展了深入的研究;通过超前地质预报、超前水平钻孔、地质测绘手段,首先查明溶洞发育规模及空间形态分布;数值模拟了岩溶隧道坍塌的机理,认识了隧道顶板溶洞块、碎石土的塌陷破坏,以及引起地面出现塌坑的过程;为确保隧道施工及运营安全,采用大管棚辅以小导管超前支护、洞内加强支护结构、三台阶七部法施工措施;隧道强支护处治措施后,隧道安全、顺利地穿越了岩溶发育区段,处治过程中未出现二次坍塌等事故。成功处理了该岩溶坍塌问题,为类似隧道溶洞块石土填充坍塌的处治提供了借鉴。

Numerical Simulation and Construction Control of Jianshan Tunnel Karst Collapses in Zunyi-Bijie Expressway

In this paper,Taking JianShan No.1 tunnel ZK1745 ＋061 karst collapse in Zunyi-Bijie expressway as an engineering example to carry out in-depth research.By advanced geological prediction and ahead horizontal drilling and geological mapping means,the cave development scale and distribution of spatial form are firstly identified.With numerical simulation,the tunnel collapse and failure mechanism are analyzed,recognizing subsidence damage of the tunnel roof cave for block stone and gravel soil,and caused the ground in the process of collapse pits.To ensure the tunnel construction and operational safety,using the large pipe shed and small catheter as forepoling and cave strengthen the supporting structures inside the cave,the three-step and the seven construction method measures are supplemented.After the treatment measures of the tunnel strong support,tunnel safety and smoothly through the karst development section,the treatment process does not appear secondary collapse and other accidents.The karst collapse problem was treated successfully,and it provides reference treatment for similar tunnel cave collapse of being filled with block stone and gravel soil.