【摘要】 取西甘池隧洞HD12+570-HD12+770段建立FLAC3D模型,模拟隧洞分段开挖及支护,将围岩参数E、μ、C、φ进行正交设计并代入模型,计算洞顶沉降量与两壁水平收敛值,与所选断面实际监测数据对比,得出与实际变形最为接近的围岩参数组合,在后续断面变形监测值中进行验证,计算误差满足精度要求,表明反演所得Ⅲ类围岩参数E=0.77×10~4MPa、μ=0.29、C=1.3MPa、φ=39°和Ⅳ类围岩的力学参数E=0.26×10~4MPa、μ=0.33、C=0.5MPa、φ=35°是可靠的。在此基础上,以锚杆排距为研究对象,对Ⅳ类围岩锚喷支护进行优化。结果表明,原锚杆支护设计方案偏于保守,锚杆排距可适当加大。更多还原

【Abstract】 This paper takes Xiganchi tunnel HD120+570-HD12+770 section for example to set up model with FLAC3 D and inputs the orthogonal designed parameters(E, μ,C and φ) to the model to simulate the process of tunnel excavation and bolt supporting. Through comparing the simulation vault settlement and horizontal convergence with the data actually monitored in the same section, we can finally find a group of parameters to make simulation results be very close to monitoring data. Then,through verification with other section monitoring data, the results show that the error is small and acceptable when E is equal to 0.77×10~4 MPa,μ is equal to 0.29, C is equal to 1.3 MPa, φ is equal to 39° for Ⅲ-classed wallrock; E is equal to 0.26×10~4 MPa,μ is equal to 0.33, C is equal to 0.5 MPa,(p is equal to 35° for Ⅲ-classed wallrock respectively. On the basis of above research,the author optimizes original bolt supporting design by changing the bolts spacing in the simulation model, and the result shows that the original design is conservative.更多还原