基于三维数值模拟的软岩超大断面隧道施工技术优化研究

发布时间：2018-08-26 15:59

【摘要】：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。
[Abstract]:In order to study the deformation caused by excavation of super-large section tunnel in soft rock stratum, based on railway design code and surrounding rock classification standard, the surrounding rock subclassification of Wanggang Mountain tunnel through rock stratum is carried out, and the direction of excavation is considered. Under the influence of complex surrounding rock condition and fault fracture zone, the three-dimensional construction process simulation was carried out by using ABAQUS finite element software, and the stress and deformation characteristics of tunnel lining and surrounding rock after excavation with three step method were obtained. On the basis of this, the method of excavation of double-sidewall tunnel is put forward, which is more suitable for controlling deformation, and its control effect is verified. Finally, the related factors affecting tunnel lining and surrounding rock deformation are analyzed, and the optimal parameters of ruler setting and initial / temporary support are obtained to control the problem of excessive deformation. The numerical results show that the two-side wall guide pit method can effectively reduce the lining and surrounding rock deformation caused by tunnel excavation. The anchor rod can play an important role in complex strata. Has an effect on the deformation of, The use of new composite pipe sheet temporary support is beneficial to the control of tunnel lining and deformation of surrounding rock. The fault fracture zone is the key part that must be paid attention to in the construction of Wanggangshan Tunnel, except for the reasonable excavation method. Other effective measures should be taken to reduce the disturbance of surrounding rock and control the deformation of excavation.
【作者单位】：中铁十六局集团第五工程有限公司;
【分类号】：U455.4

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