贵瓮高速公路建中隧道施工难点及治理措施

溶腔、洞室和软弱破碎带是岩溶地区隧道施工的难点和重点。贵瓮高速建中隧道在施工过程中出现了围岩与设计情况不符以及溶洞塌方等问题,严重影响了施工进度。为此,通过对国内典型岩溶隧道设计施工案例进行分析借鉴,结合建中隧道的工程地质条件,在围岩与设计情况不符段进行方案修改,加强支护;在溶洞塌方段进行掌子面封闭、深孔注浆、回填混凝土等治理措施。经采取上述措施后,拱顶沉降和隧道周边位移均小于控制标准,效果良好。

Construction Difficulties and Treatment Measures of Jianzhong Tunnel on Guiweng Highway

Dissolved cavity,cavern,soft and shear zone are difficult points in the construction of karst tunnels. During the construction of Jianzhong tunnel on Guiweng highway,great differences appeared between the local surrounding rock conditions and those indicated in the design and some caverns were collapsed. These seriously affected the construction progress. Therefore,through analyzing the domestic typical karst tunnel design and construction cases,based on the engineering geological conditions of Jianzhong tunnel,programs in the area with conflicted surrounding conditions against the design are modified with reinforced support. In the area of dissolved cavern collapse,such measures are taken as tunnel face closing,deep hole grouting and concrete backfilling. With the measures taken,crown settlement and tunnel inner perimeter displacement are less than the control limits and the effect is good.