论文部分内容阅读
通过对长坪隧道出口浅埋软弱围岩段施工的跟踪监测,分析和总结了围岩变形、锚杆轴力、围岩压力、钢拱架内力、喷射砼与二次衬砌砼结构的承载状况,研究结果表明:该洞段采用台阶分部开挖法施工是适宜的,它能较为有效地抑制围岩的变形;隧道拱部施筑的锚杆作用和效果明显大于边墙部位的锚杆,二次衬砌砼承载结构所受到的压力约为其同部位围岩压力的1/3～1/2.图8,参8.
Through the tracking and monitoring of the construction of shallow and weak surrounding rock sections at the exit of Changping tunnel, the deformation of surrounding rock, the axial force of rock bolts, the pressure of surrounding rock, the internal force of steel arch frame, the bearing conditions of sprayed concrete and secondary lining concrete structure are analyzed and summarized The results show that it is suitable for the section to be constructed by the step excavation method, which can restrain the deformation of the surrounding rock more effectively. The function and effect of the anchor made by the tunnel arch is obviously greater than that of the bolt The pressure applied to the secondary lining of the concrete bearing structure is about 1/3 to 1/2 of the surrounding rock pressure of the same site.