西南煤系地层山区高位岩质滑坡冲击铲刮机理研究

Affected by Yanshan tectonic movement, NNE-NE trending carbonate fold mountain bodies are formed in coal measure strata in Southwest China. The regional geological environment is complex, and human engineering activities are intense, hence, the high position rock landslide has become one of the geological disasters with extreme destructive power. This type of high position landslide disaster has two main characteristics and difficult points. On the one hand, the main body impacted erodible basic rock and soil mass material, so that the scale of slide body was enlarged, and the degree of landslide damage was also increased. On the other hand, dynamic contact leads to landslide disaster chain, which increases the difficulty of risk assessment. The purpose of this project is to study the dynamic mechanism of high position rock landslides in Southwest coal measure stratigraphic mountain area. The main contents are as follows: (1) through landslide field investigation and chute model test, the geomechanical model is established, and the impact erosion mode is then to reveal about high position rock landslide under different underlying rock and soil mass material. (2) the impact erosion mechanism between active impact and passive yield is studied by mathematical mechanics model derivation from quasi-static to dynamic. (3) to carry out the quantitative analysis of inversion and prediction of high position rock landslide in southwest coal measure strata under impact erosion effect. The research results will provide important theoretical significance and technical support for disaster prevention and mitigation in Southwest coal measure stratigraphic mountain area.

受燕山构造运动影响，我国西南煤系地层山区多形成NNE-NE向的碳酸盐岩褶皱山体，区域地质环境复杂，人类工程活动强烈，高位岩质滑坡成为具有极强破坏力的地质灾害之一。此类高位滑坡灾害主要有两个特点，也是研究的难点，一是铲动周围和下部岩土体，使滑体规模放大，增加了滑坡危害程度；二是动力接触导致滑坡链式成灾，增加了危险评估难度。本项目拟针对我国西南煤系地层山区高位岩质滑坡冲击铲刮动力学机理开展研究，主要包括：（1）通过滑坡现场调查和滑槽模型试验，建立地质力学模型，揭示高位岩质滑坡对不同下垫层岩土体的冲击铲刮模式；（2）通过准静态到动态的数学力学模型推导，研究主动冲击和被动屈服之间的冲击铲刮力学机理；（3）开展冲击铲刮效应下的西南煤系地层山区高位岩质滑坡的反演和预测的定量化分析。研究成果为西南煤系地层山区防灾减灾提供重要理论意义和技术支撑。

我国西南煤系地层山区地质环境复杂，人类工程活动强烈，高位岩质滑坡成为具有极强破坏力的地质灾害之一。此类高位滑坡灾害主要有两个特点，也是研究的难点，一是铲动周围和下部岩土体，使滑体规模放大，增加了滑坡危害程度；二是动力接触导致滑坡链式成灾，增加了风险评估难度。项目开展过程中围绕高位岩质滑坡的冲击铲刮机制开展研究。取得以下四点成果进展：1）采用现场调查和工程地质分析方法建立高位岩质滑坡的高位剪出-凌空飞行-冲击铲刮-碎屑堆积的运动地质模型。2）采用滑槽模型试验和离散元数值模拟技术，根据冲击滑体和被铲刮岩土材料的性质差异提出嵌入铲起模式、裹挟夹带模式、平推滑移模、式和冲击飞溅模式四种冲击铲刮模式。3）结合布辛内斯克(Boussinesq)和西罗提(Cerruti)解推导了对竖向和水平向冲击荷载作用下铲刮塑性破坏区边界的临界判别方程。4）针对重庆彭水马岩高位危岩，采用数值模拟方法对冲击铲刮效应下的高位岩质滑坡运动堆积过程进行空间预测数值分析。综上研究成果为西南煤系地层山区防灾减灾提供重要理论意义和技术支撑。