郭朋瑜, 闫兴田, 吉锋, 等. 2023. 四川茂县新磨村滑坡启动机制物理模拟试验研究[J]. 工程地质学报, 31(1): 154-164. doi: 10.13544/j.cnki.jeg.2020-423.
    引用本文: 郭朋瑜, 闫兴田, 吉锋, 等. 2023. 四川茂县新磨村滑坡启动机制物理模拟试验研究[J]. 工程地质学报, 31(1): 154-164. doi: 10.13544/j.cnki.jeg.2020-423.
    Guo Pengyu, Yan Xingtian, Ji Feng, et al. 2023. Physical simulation test of initiation mechanism for Xinmocun landslide in Maoxian, Sichuan[J]. Journal of Engineering Geology, 31(1): 154-164. doi: 10.13544/j.cnki.jeg.2020-423.
    Citation: Guo Pengyu, Yan Xingtian, Ji Feng, et al. 2023. Physical simulation test of initiation mechanism for Xinmocun landslide in Maoxian, Sichuan[J]. Journal of Engineering Geology, 31(1): 154-164. doi: 10.13544/j.cnki.jeg.2020-423.

    四川茂县新磨村滑坡启动机制物理模拟试验研究

    PHYSICAL SIMULATION TEST OF INITIATION MECHANISM FOR XINMOCUN LANDSLIDE IN MAOXIAN, SICHUAN

    • 摘要: 2017年四川省茂县新磨村滑坡的启动具有明显的“锁固段”效应。在现场调查基础上,采用高强度脆性材料制作斜坡模型,开展物理模拟试验,重现滑坡变形破坏过程,分析新磨村后山高位顺层滑坡在反倾节理和潜在滑移破裂面控制下的启动机制,结合“锁固段”岩体变形破坏特征、变形监测数据和声发射信号,研究滑坡临滑前兆。试验发现:受上部滑体推挤,滑源区前部“锁固段”岩体沿反倾节理鼓胀剪出,在坡表形成鼓胀裂缝,在斜坡内部形成顺坡向拉裂面,两组破裂面组合形成阶梯状破坏面,构成“锁固段”岩体破坏边界条件。斜坡在上部滑移块体推挤下,中部形成向临空面高速启动的弹射块体,并带动下部倾倒块体向坡外运动,滑坡启动。故对于此类滑坡,可将沿反倾节理剪出形成的鼓胀裂缝视为宏观临滑前兆;同时在“锁固段”屈服阶段,坡表与坡顶的位移比值随时间先快速增长、后平缓,表征滑面逐渐贯通,滑坡各部位变形逐渐趋于协同,滑坡即将失稳。该比值时序曲线的斜率趋近于零可视为此类滑坡的临滑前兆。研究结论对发育反倾节理的顺层边坡失稳预警有理论和实践意义。

       

      Abstract: In 2017, the initiation of Xinmocun landslide in Maoxian, Sichuan had obvious "locking section" effect. On the basis of field investigation, we adopt high strength brittle material to make slope model, and used it to carry out physical simulation test for reproducing the process of landslide deformation and failure. We analyze the initiation mechanism of Xinmocun landside under the control of the anti-dip joint and the potential slip fracture surface. We combined the deformation and failure characteristics of the rock mass of the "locking section", and the deformation monitoring data and acoustic emission signals. We found some precursors of landslide. The experiment showed the follows: Due to the push of the upper slide, the rock mass of the "locking section" in the front of the sliding source area expanded and sheared along the anti-dip joints, which formed a bulging fracture on the slope surface and a downslope tension crack surface in the interior of the slope. Next the two groups of fractures were combined to form a stepped failure surface, which formed the boundary condition of rock mass failure in the "locking section". Under the pushing of the upper slide, the middle part of the slope formed the ejection block with high speed. Within the meantime, the lower dumping block toppled over the outside. Subsequently the landslide failed. Therefore, we conclude that the bulging cracks that were formed along the anti-dip joints can be regarded as the macroscopic precursors of this kind of landslides. At the same time, in the yield stage of the "locking section", the displacement ratio between the slope surface and the top increases rapidly and then flattens out with time, representing the gradual penetration of the slide surface. Hence, the ratio tends to be stable with time, which can be used as a precursor of the landslide. The research conclusions have theoretical and practical significance for warning of instability of bedding slopes with anti-dipping joints.

       

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