岩溶地区公路隧道穿越大型溶洞处治措施分析

Analysis on Treatment Measures for Highway Tunnel Passing Through Karst Caves

以贵州岩溶发育区域的某高速公路隧道为工程背景,在介绍隧道施工所揭露的溶洞基本情况的基础上,针对隧道底面以下存在巨型溶洞回填不起效果的情况,采取新的处治方案并对其进行数值计算分析。结果表明:①隧道侧面溶洞对隧道围岩位移扩展影响较大,需要加固处理,在溶洞边缘添加加固部件能够对位移起到良好的限制作用,本工程各监测点位移、应力均远小于《公路隧道设计规范》规定值,工程安全;②采用工字钢横跨隧道底面以下溶洞至溶洞墙壁,工字钢上部设钢筋混凝土板能够有效解决巨型溶洞回填不起效果的技术难题。研究成果对于存在相似问题的隧道工程能够起到很好的借鉴作用。

This article takes a highway tunnel in the karst development area of Guizhou as the engineering background,on the basis of introducing the basic situation of the karst cave exposed by the tunnel construction,for the existence below the tunnel bottom if the backfill of the giant karst cave is not effective.A new treatment plan and numerical calculation were performed.The results show that:①The side caves of the tunnel have a great influence on the displacement expansion of the surrounding rock of the tunnel,which requires reinforcement treatment.The addition of reinforcement components at the edge of the cave can play a good role in limiting the displacement.The displacement and stress of each monitoring point in this project are far less than"Highway Tunnel Design Code"stipulated value,and the engineering is safe;②I-beam is used to cross the cave below the tunnel bottom to the cave wall,and the reinforced concrete slab above the I-beam can effectively solve the technical problem that the backfill of the giant karst cave is not effective.The research results can serve as a good reference to other karst tunnel projects.