黄土地层大跨区间隧道新奥法施工格栅拱架受力分析

发布时间：2019-01-07 20:11

【摘要】：兰州市轨道交通一号线东岗站后配线段黄土地层大跨区间隧道采用双侧壁导坑法施工,根据不同断面的监测数据对比分析初期支护围岩压力和格栅拱架钢筋应力的分布规律。结果表明:格栅拱架支护作用明显,钢筋应力最大值为108.27 MPa,位于隧道拱腰处,满足设计要求;测试断面拱腰和拱肩处围岩压力、钢筋应力相对较大,施工过程中应加强变形监测和控制;初期支护局部变形较大时采用临时钢支撑辅助加固效果明显;整个断面格栅拱架钢筋应力分布不均匀,格栅拱架的分段架设与连接须牢固,以提高结构的整体性;仰拱施作完毕7 d后,整个断面围岩压力和格栅拱架钢筋应力趋于稳定。
[Abstract]:The double-sidewall diversion pit method is used to construct the large-span loess layer inter-area tunnel of Donggang Station of No. 1 Railway Line of Lanzhou City. According to the monitoring data of different sections, the distribution law of the initial supporting surrounding rock pressure and the reinforcement stress of the grid arch frame are compared and analyzed according to the monitoring data of different sections. The results show that the support effect of grid arch frame is obvious, and the maximum stress of steel bar is 108.27 MPa, which is located at the arch waist of tunnel, which meets the design requirements. The stress of steel bar is relatively large in the test section arch waist and arch shoulder, the deformation monitoring and control should be strengthened in the construction process, when the local deformation of initial support is large, the effect of auxiliary reinforcement with temporary steel support is obvious. The stress distribution of the steel bar in the whole section grid arch frame is uneven, the segmental erection and connection of the grid arch frame must be firm in order to improve the integrity of the structure, and the pressure of surrounding rock of the whole section and the stress of the steel bar of the grid arch frame tend to be stable 7 days after the completion of the inverted arch.
【作者单位】：兰州交通大学土木工程学院;兰州交通大学甘肃省道路桥梁与地下工程重点实验室;兰州交通大学甘肃省轨道交通力学应用工程实验室;
【基金】：国家自然科学基金(51268030) 长江学者和创新团队发展计划(IRT_15R29)
【分类号】：U455.48

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