| 基于模型试验的动水驱动型顺层岩质滑坡启滑机制初探 |
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| 引用本文： | 唐雅婷,谭杰,李长冬,李炳辰,周文娟.基于模型试验的动水驱动型顺层岩质滑坡启滑机制初探[J].地质科技通报,2022,41(6):137-148. |
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| 作者姓名： | 唐雅婷 谭杰 李长冬 李炳辰 周文娟 |
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| 作者单位： | a.中国地质大学(武汉) 工程学院, 武汉 430074 |
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| 基金项目： | 国家自然科学基金重大项目42090054国家自然科学基金优秀青年科学基金项目41922055 |
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| 摘 要： | 动水驱动型顺层岩质滑坡数量多、灾害频发、危害大, 是滑坡地质灾害领域的研究重点, 但目前对于滑坡启滑机制的认识仍不充分, 滑坡的准确预报还面临巨大挑战。鉴于此, 以含软弱夹层的中倾角顺层岩质滑坡为研究对象, 通过构建理想的单层滑带滑坡物理模型, 开展了一系列动水作用下的滑坡模型试验研究。结果表明, 动水作用下顺层岩质滑坡从开始变形至失稳滑动需经历初始变形、缓慢变形、加速变形和失稳破坏4个阶段, 而各个阶段的演化特征与滑面粗糙度和倾角密切相关。滑面倾角越大或粗糙度越小, 滑坡体从开始变形至失稳滑动所需的时间则越短; 相应地, 坡体加速变形阶段越不明显, 滑坡破坏的突发性越强。滑带内的渗流冲蚀作用会使滑带土中的骨料流失, 导致其抗剪强度降低, 进而引发坡体滑动。与此同时, 上覆坡体的压剪作用以及变形演化过程亦将反过来影响冲蚀强度。基于滑带土黏聚力随水力梯度和冲蚀时间的变化关系, 提出了渗流驱动下滑带土黏聚力演化模型, 可较好地描述滑带土黏聚力的退化过程。滑面粗糙度的存在不仅显著影响了滑带的冲蚀劣化规律, 还改变了滑带不同区域的破坏模式。此外, 通过考虑滑面粗糙度对滑带不同区域破坏模式的影响, 开展了动水多效应关联分析, 建立了滑坡地质体力学分析模型, 实现了动水作用下顺层岩质滑坡动态稳定性的有效评估。本研究成果可为实际动水驱动型顺层岩质滑坡的预测和防治提供理论参考。
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| 关 键 词： | 顺层岩质滑坡 模型试验 动水作用 强度劣化 启滑机制 |
| 收稿时间： | 2022-05-23 |
Preliminary study on the initiation mechanism of hydrodynamic-driven bedding rock landslides based on physical model tests |
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| Affiliation: | a.Faculty of Engineering, China University of Geosciences(Wuhan), Wuhan 430074, Chinab.Badong National Observation and Research Station of Geohazards, China University of Geosciences(Wuhan), Wuhan 430074, China |
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| Abstract: | Hydrodynamic-driven bedding rock landslides are the focus of research in the field of landslide geological hazards due to their large number, frequent disasters, and excessive harm. However, the understanding of the initiation mechanism of landslides is still insufficient, and the accurate prediction of landslides still faces great challenges. Because of this, this paper takes moderate-dip angle bedding rock landslides with weak interlayers as the research object and conducts a series of landslide model tests under the action of hydrodynamics by constructing an ideal single-layer landslide physical model. On this basis, the macroscopic deformation evolution process of the landslide and the erosion degradation characteristics of the slide zone soil is analyzed in depth. The results show that the failure of bedding rock landslides is associated with the slip surface roughness and dip angle and can go through four stages: the initial deformation stage, uniform deformation stage, accelerated deformation stage, and failure stage.The seepage erosion in the sliding zone causes the loss of aggregates, which reduces the shear strength and causes the slope to slide. Simultaneously, the compression-shear action and the deformation of the overlying slope also adversely affect erosion strength.Based on the variation law of soil cohesion in the sliding zone with hydraulic gradient and erosion time, a seepage-driven evolution model of soil cohesion in the sliding zone is proposed, which can describe the degradation process of soil cohesion in the sliding zone well. The existence of sliding surface roughness not only significantly affects the deterioration law of the sliding zone, but also changes the failure modes of different regions of the sliding zone. By considering the influence of the roughness on the failure modes of different areas of the sliding zone, the multi-effect correlation analysis of dynamic water is carried out, and the mechanical model of the landslide is established, which realizes the effective evaluation of the dynamic stability of the landslide. The research achievements in this study can provide a theoretical reference for predicting and preventing actual hydrodynamic-driven bedding rock landslides. |
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