高速远程滑坡早期识别研究

As a kind of geological hazards , massive fragmented materials will be migrated and deposit on a long distance in a very short time while a high-speed long-runout landslide be triggered. Misjudgment will lead to a devastating consequence, so it need for well-established theory, methods and techniques to guide the early identification of high-speed long-runout landslide. Typical landslides will be taken as example of case in the proposal. The engineering geological methods, modern testing techniques, numerical simulation and systems analysis methods will be applied to study on the formation conditions of high-speed long runout landslide, to analyze the composition, microstructure, thermophysical properties and the nature of resistance to stress corrosion of slipping zone rock-or-soil of landslide to establish 3D engineering geological model, physicalmechanical model of typical landslides. Techniques of multi-field coupling will be utilized to analysis the stress and strain accumulation of the potential sliding mass and the process of energy accumulation, in order to promote the understanding the triggering and starting mechanism of high-speed long-runout landslide. Through combined with the digital elevation model before and after the sliding, so as to simulate the migration and deposition process of massive fragmented materials on the basis of understanding energy dissipation mechanism of the migration and deposition channel. Based on the reverse-analysis, it reveals the law of stress-strain accumulation, quickly deformation and failure, the high-speed long-runout movement process, characteristics of accumulation sequence and spatial distribution of the fragmented materials of rock-or-soil mass of slides on the different conditions-combination mode. Finally realize to the early identification of the high-speed long-runout slides based on the formation mechanism and numerical simulation.

高速远程滑坡作为一种在极短时间内完成远距离运移并堆积大量碎裂物质的地质灾害，如果误判将导致毁灭性的后果。因此亟需行之有效的理论、方法和技术来指导高速远程滑坡的早期识别。本项目以典型滑坡为例，应用工程地质方法、现代测试技术、数值仿真以及系统分析等方法，研究高速远程滑坡的形成条件，分析滑带岩土以及滑体的物质组成、微观结构、热物理性质、抗应力腐蚀能力，建立典型滑坡的三维工程地质模型和物理力学模型；运用多场耦合分析技术，分析潜在滑体应力应变积累以及能量积聚过程，揭示高速远程滑坡触发启动机制；结合滑坡前后数字高程模型，分析运移堆积通道的耗能机制，模拟大量碎裂物质运动堆积过程。从而在反分析的基础上，揭示不同条件组合模式下滑坡岩土体应力应变积累、快速变形破坏、高速远程运动规律，以及碎裂物质的堆积序列及空间分布特征。最终实现基于形成机理分析与数值仿真模拟的高速远程滑坡的早期识别。

以重庆武隆鸡尾山滑坡和贵州关岭大寨滑坡为主要研究对象，开展高速远程滑坡形成机制和早期识别研究。综合野外地质调查、岩土物理力学试验、数值模拟等手段，剖析高速远程滑坡的启动机制及运动堆积过程，从工程地质条件入手，甄选高速远程滑坡早期识别指标，建立高速远程滑坡早期识别模型，并开展实例应用。得到如下成果：.1..大寨滑坡启动的有利条件主要为碎裂岩体结构条件以及滑坡体的高势能。斜坡后缘拉裂隙以及强降雨共同对大寨滑坡失稳起到关键作用。天然工况下大寨滑坡的安全系数为1.18，强降雨条件下滑坡的安全系数为0.92。.2..鸡尾山滑坡初始动能主要源于滑带弹性应变能的释放。依据鸡尾山滑坡启动弹冲机制，推导了滑坡启动速度计算公式，计算表明，鸡尾山滑坡启动速度为1.2611m/s。.3..对大寨滑坡运动过程中的重力场、温度场演化过程和变化趋势进行了数值模拟。结果表明：运动过程中温度持续升高；当重力场和温度场均不变化时，滑坡体停积。模拟得到的滑体停积图，与遥感影像图基本一致，整个运动堆积过程持续时间167s，与调查结果吻合。说明基于多场耦合作用的数值模拟，可以较好地预测预报高速远程滑坡的运动时间过程与堆积范围。.4..以岩石单轴、三轴实验结果为基础，借助PFC3D软件对岩石力学试验进行模拟，得到与实验结果相匹配的PFC3D模拟微观参数。运用该微观参数对不同碎裂级配条件下关岭大寨高速远程滑坡的堆积范围进行模拟，对比分析表明：等粒滑坡模型比级配滑坡模型堆积范围更大，滑坡体碎裂后的物质级配决定其堆积范围的关系。.5..结合大量实际资料的统计分析与典型滑坡实地考察，将高速远程滑坡的高速运动与远程堆积特性的主要影响因素归纳为：崩滑体规模、潜在滑动面（带）、剪出口类型、地形条件、崩滑体相互碰撞及推动作用。.6..从工程地质条件入手，基于高速远程滑坡形成机制，构建了高速远程滑坡早期识别指标体系，借助突变级数理论模型，建立了高速远程滑坡早期识别的突变模型。实例应用表明，本方法具有可操作性和实用性。