The surrounding rocks of Wanggangshan Tunnel are sub-classified based on railway design standards and surrounding rock classification standards;the tunnel construction process is simulated by finite element software ABAQUS considering excavation direction,complex surrounding rock conditions and fault and fracture zone;and the characteristics of stress and deformation of tunnel lining and surrounding rock after three-bench excavation are obtained.And then,the double-side drift method which is favourable for deformation control is put forward;and the deformation control effect is verified.Finally,the influencing factors on deformation of tunnel lining and surrounding rock are analyzed;and the optimal advancing parameters and primary/temporary support mode are obtained.The numerical calculation results show that:1) The excavation-induced deformation of tunnel lining and surrounding rock can be effectively controlled by double-side drift method.2) The anchor bolt plays a significant role in complex strata.3) Cyclic advancing and primary support strength have influence on excavation induced deformation;and the deformation of tunnel lining and surrounding rock can be effectively controlled by using new composite segment primary support.4) The fault and fracture zone is the key to Wanggangshan Tunnel;as a result,rational excavation method and relevant auxiliary surrounding rock disturbance reducing methods should be adopted.%为研究超大断面隧道在软岩地层中开挖施工引起的变形情况,基于铁路设计规范和围岩分级标准对王岗山隧道穿越岩层进行围岩亚分级,通过考虑开挖方向、复杂围岩条件及断层破碎带的影响,利用ABAQUS有限元软件开展三维施工过程模拟,获得三台阶法开挖后的隧道衬砌及围岩受力及变形特征.在此基础上,提出采用更适宜控制变形的双侧壁导坑开挖法,并对其控制效果进行验证.最后,分析影响隧道衬砌和围岩变形的相关因素,得到利于控制变形过大问题的最优进尺设置参数及初期/临时支护形式.数值计算结果表明:1)双侧壁导坑法能够有效降低隧道开挖引起的衬砌及围岩变形;2)锚杆在复杂地层中能够发挥重要作用;3)循环进尺和初期支护强度均对施工引起的变形存在影响,使用新型复合管片临时支护有利于控制隧道衬砌及围岩变形;4)断层破碎带是王岗山隧道施工必须重视的关键部位,除采用合理的开挖工法外,还应辅以其他降低围岩扰动进而控制开挖变形的有效措施.
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