【作者】 韦啸； 高文学； 石连松； 曹晓立；

【Author】 WEI Xiao;GAO Wenxue;SHI Liansong;CAO Xiaoli;College of Architecture and Civil Engineering,Beijing University of Technology;

【机构】 北京工业大学建筑工程学院；

【摘要】 针对石峡隧道斜井浅埋段掘进施工实际情况,运用有限元软件进行了施工过程稳定性模拟,对台阶法开挖下隧道拱顶沉降、拱底隆起、围岩的侧向收敛变形、围岩应力应变和隧道支护结构的受力情况进行了模拟分析,来研究斜井浅埋段隧道开挖施工对围岩、支护结构的稳定性影响。研究表明:1)台阶开挖后,拱顶和拱腰位置衬砌内力值较大,拱顶位置产生拉力,拱腰位置产生压力,施工时应对该位置进行重点支护,防止衬砌受压或受拉破坏。2)大部分锚杆受拉力作用,锚杆悬吊作用明显。3)隧道台阶开挖时,拱腰位置应变值较大,且拱腰位置普遍存在压应力;上台阶开挖后,拱顶存在范围较广的拉应力。4)隧道的浅埋因素对拱顶沉降及隧道上方地表沉降影响较大。同时,台阶开挖后地表围岩隆起不可忽视,施工时应避免应地表围岩隆起而造成衬砌的破坏。更多还原

【Abstract】 Aiming at the actual situation of excavation in the shallow section of inclined shaft of Shixia Tunnel,the stability simulation of construction process was carried out by using finite element software.The settlement of tunnel vault,arch bottom uplift,lateral convergence deformation of surrounding rock,stress and strain of surrounding rock and stress of tunnel support structure were simulated and analyzed under the step excavation method,so as to study the influence brought by the excavation construction of inclined shaft shallow section tunnel to the surrounding rock and support structure.Results showed that:1) After the step excavation,the internal force of the lining in the vault and waist position was larger,the tension was generated at the vault position and the pressure was generated at the waist position,where should be provided with key support to prevent the lining from being compressed or damaged by tension during the construction.2) Most bolts were under tension,and the suspension effect was obvious.3) When excavating tunnel steps,the strain value of arch waist position was larger,and the compressive stress existed generally in the arch waist position.After the excavation of the upper step,there was a wide range of tension stress in the vault.4) The shallow burial factors of the tunnel had great influence on the settlement of the vault and the ground surface above the tunnel.At the same time,the uplift of surface surrounding rock after step excavation could not be neglected.The lining damage caused by the uplift of surface surrounding rock should be avoided during construction.更多还原