张家山隧道浅埋偏压段施工和量测技术研究

Study on Construction and Monitoring-measurement of Shallow Buried and Unsymmetrical Loaded Section in Zhangjiashan Tunnel

浅埋偏压段隧道不良地质条件给施工造成安全隐患,也是决定整条隧道施工成败的关键。重庆云阳至万州高速公路张家山隧道出口部分处于严重浅埋偏压段,讨论了该段施工设计和施工工艺,包括地表注浆预加固、超前注浆锚杆支护、单侧预切槽镶嵌拱架式进洞的分部开挖法、喷锚挂网支护和围岩监控量测信息反馈与预测预报等,成功解决了施工中的难题。围岩变形和地表沉降监测分析结果表明,地表预注浆加固、分部开挖和及时施做初期支护等措施能有效控制围岩松弛,确保施工顺利进行。

Poor geological conditions of shallow buffed and unsymmetrical loaded section caused potential safety problems on construction, which is critical to the success of tunnel construction. Construction design and process that had been succeeded in solving the problems during construction were discussed by example of Zhangjiashan Tunnels which portal was shallow buried and unsymmetrical loaded section, from Wanzhou to Yunyang Expressway in Chongqing, including ground surface slurry injection for strengthening rock and soil mass, preset grouting and bolts technology, partial excavation method of the steel arch embedded in unilateral pre-cutting groove, the bolting and shooting concrete with wire mesh and information feedback and the forecast by monitoring-measurement to surrounding wall rock. Through analyzing rock deformation and surface subsidence monitoring, it can be shown that measures, such as the ground surface slurry injection for strengthening rock and soil mass, partial excavation method and primary support of tunnel installed in time, can effectively control rock relaxation to ensure the smooth construction.