公路软岩隧道半刚性网壳锚喷衬砌新技术研究

Study on Half-rigidity Shell Bolting Shotcrete of Soft Rock Tunnels

用钢筋焊接成的格构式金属棚子作为隧道支护喷层内部的加强撑,与型钢支架一样,其架间仍是弱支护部分,难以承受较大的变形地压,所以隧道工程中通常仅用其作为施工期间的临时衬砌结构。文章设计出新型网壳喷层衬砌并进行整架结构试验,完成网壳锚喷支架工业性试验,达到用较少材料又提高喷层支撑能力与让压的目标,证明网壳锚喷支架是结构合理、工艺简单、能承受高应力的新型支架。

The lattice-shaped metal brace welded with reinforcing steel bar replaced the profiled bar used as the reinforcement inside the supporting shotcrete of the tunnel.However, similar to the profiled bar bracing, the lattice-shaped brace also has the deficiency that the concrete between reinforcement bars can't support the pressure caused by large soil deformation for its weak strength. So it was only used as temporary lining. The test of the shell bolting and shotcrete trestle used in the soft rock tunnels under high stress, was introduced. The practical test result of the new bracing shows that it can improve the bracing ability with less material.The shell bolting and shotcrete support is a well-structured one,which can sustain great ground stress and can be constructed easily.