古石背隧道岩溶段的综合治理

溶洞洞穴的存在易造成隧道围岩塌陷压垮二衬或悬空造成开裂等病害,给隧道施工、运营安全造成威胁。针对古石背隧道施工在隧道拱顶、侧面、拱脚、仰拱底部等位置出现岩溶洞穴的情况,根据溶洞对隧道不同影响和施工条件,采用了清除充填物、回填片石夯实或砼、注浆加固填充物、钢筋砼护拱、钢筋砼板跨越、封闭地表塌陷、疏排地表水等综合治理措施,施工结果表明治理是成功的。

Comprehensive Treatment for the Karst in the Gushibei Tunnel

The existence of karst caves can easily lead to collapse of surrounding rock then crush the permanent concrete lining or cause crack,etc.,which would pose a threat to tunnel construction and operation safety.During the construction of Gushibei tunnel,karst caves were found at the vault,side,springing and invert bottom,etc.According to different impacts of the karst caves on the tunnel and construction conditions,some engineering comprehensive treatment measures were taken,such as clearing away the filling, backfilling and ramming rubbles or concrete, grouting fillings, using reinforced concrete protecting arch, spanning by reinforced concrete plate, closing surface subsidence and properly draining surface water. The construction result shows that the treatment is successful.