【摘要】 为了获得开挖过程中隧道结构体应力、应变和位移规律,以渝黔二期笔架山隧道北端洞口段实态建模,采用有限元程序对施工全过程进行了三维弹塑性数值模拟,并与现场实测数据进行了比较.研究结果表明,开挖对围岩影响较大的范围在开挖面四周5m以内,且上台阶开挖的影响大于下台阶开挖;围岩沉降和水平位移在开挖前已完成1 /3;围岩塑性区位于开挖面前1. 5m范围内,锚杆主要受本施工段上台阶开挖的影响.更多还原

【Abstract】 In order to obtain the regularities of stress, strain and displacement of tunnel structures during excavation, the northern end of Bijiashan tunnel in the 2nd stage Yu Qian project was modeled and its construction process was numerically simulated with 3D elasto plastic finite element method (FEM). Comparison between simulated and in situ tested results shows that the range with a great influence of tunnel excavating on surrounding rock is 5 m around an excavation face, excavation of the upper bench has a greater effect than that of the lower bench, and one third of total settlement and horizontal displacement of surrounding rock has generated before excavating. In addition, the plastic zone in surrounding rock ranges 1.5 m in the front of an excavating face, and rock bolts are mainly influenced by the excavation of the upper bench in the current construction step.更多还原