跨断层隧道围岩渐进性破坏模型试验及数值模拟

发布时间：2018-06-06 16:24

本文选题：隧道工程 + 软弱围岩　；参考：《岩石力学与工程学报》2016年03期

【摘要】：断层及其破碎带是隧道开挖过程中常见的不良地质现象,也是围岩不稳定且容易出现事故的地段。以山区隧道施工中常见的IV级围岩为参照对象,利用地质力学模型试验和数值模拟研究跨断层隧道施工过程中围岩的渐进性破坏过程及其受力变形特性。研究结果表明:(1)位于拱顶之上的断层下盘岩体在隧道开挖后呈悬挑状态,且在靠近断层部位易出现拉裂缝;(2)隧道开挖使得上覆荷载向隧洞左、右两侧转移,从而导致拱腰以下的岩体往往率先剪切破坏,尤以断层下盘一侧岩体为甚;(3)隧道开挖将引起围岩应力重分布,若调整后的围岩应力超出岩体自身强度极限时,洞周岩体就会塌落成拱,且位于塌落范围内的岩体切向应力呈"跌落式"下降,此特征可用于判断岩体塌落范围;(4)隧道开挖后,由于断层的阻隔作用,岩体应力在跨越断层上、下盘时呈不连续、非线性分布的特征。
[Abstract]:Faults and their broken zones are common bad geological phenomena during tunnel excavation, and they are also unstable and prone to accidents. Taking the IV grade surrounding rock as the reference object in the construction of mountain tunnel, the progressive failure process of surrounding rock and its mechanical deformation characteristics during the construction process of cross fault tunnel are studied by using geomechanical model test and numerical simulation. The results show that the rock mass of fault footwall on top of arch is overhanging after tunnel excavation, and the tension crack is easy to appear near the fault) tunnel excavation causes the overlying load to transfer to the left and right sides of the tunnel. As a result, the rock mass below the arch often takes the lead in shear failure, especially in the side of the fault footwall. The excavation of the tunnel will cause the stress redistribution of the surrounding rock. If the stress of the adjusted surrounding rock exceeds the limit of the strength of the rock mass itself, The rock mass around the cave will collapse into arch, and the tangential stress of rock mass located in the area of collapse will be "dropped". This feature can be used to judge the rock mass stress on the cross fault after excavation of the tunnel. The discontinuous and nonlinear distribution of the lower disk is observed.
【作者单位】：同济大学道路与交通工程教育部重点实验室;同济大学岩土与地下工程交通教育部重点实验室;中国矿业大学力学与建筑工程学院;深圳市交通公用设施建设中心;
【基金】：国家自然科学基金重点项目(41130751);国家自然科学基金资助项目(51174197) 西部交通建设科技项目(2011ZB04)~~
【分类号】：U456

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