软岩隧道支护结构受力特征分析

为研究软岩隧道支护结构的受力特征，优化软岩隧道支护方案及施工工法，以龙怀高速石凹顶隧道为依托，选取浅埋段、深埋段、破碎带断面进行现场监测，从支护结构受力的变化规律、空间分布、对比验证等，对围岩压力、接触压力、初支混凝土应力、钢拱架应力等进行系统研究。结果表明：软岩隧道采用CD法比预留核心土法施工扰动小，作用于支护结构上的荷载也相应偏小；作用于支护结构上的荷载与围岩破碎程度及所受构造应力大小呈正比关系；隧道施工中应尽量减少不必要的围岩扰动，充分发挥围岩自承能力。

Analysis of Stress Characteristics of Soft Rock Tunnel Supporting Structure

In order to study the stress characteristics of the supporting structure of soft rock tunnel and optimize the supporting scheme and construction method of soft rock tunnel, relying on the Longhuai expressway Shiaoding tunnel, the shallow buried section, deep buried section, and fracture zone section for field monitoring are selected. From the aspects of the stress variation law ,spatial distribution, and comparative verification of the supporting structure, the pressure of surrounding rock, contact pressure, stress of initially supported concrete and stress of steel arch frame are systematically studied. The research results show that for soft rock tunnels, the CD method has less disturbance than the reserved core soil method, and the load acting on supporting structure is correspondingly smaller.The load acting on the supporting structure is proportional to the crushing degree of surrounding rock and the tectonic stress. In tunnel construction, unnecessary disturbance of surrounding rock should be reduced as far as possible, and the self-supporting capacity of surrounding rock should be brought into full play.