降雨诱发浅层滑坡的动态危险性评价模型与方法研究

The shallow landslides induced by the rainfall have the characteristics of regional and multiple occurrence, which can cause great catastrophic losses in a short period of time. The dynamic and diversity of the rainfall process directly affect the location and intensity of the landslide. Landslide hazard assessment is the basis of landslide risk research, and also is an important means to realize landslide disaster prediction, and then develop prevention and control plan. Based on the mechanism of the Effects of rainfall on the evolution of shallow landslides, the geological mechanism and deformation process of landslide are taken into account in the study of landslide hazard assessment, and the method of quantifying the intensity of regional landslide disaster is determined. Based on the statistical analysis of landslide hazard data in Wuling Mountain area, the generalized model of soil structure is established, the infiltration characteristics of different soil structure models are analyzed, and the law of rainwater movement between different parts of slope and its adjacent slope is studied. The indoor physical model test is carried out to construct the shallow landslide The paper puts forward the quantitative expression method of landslide intensity during the process of deformation and instability of shallow landslide, establishes the dynamic prediction method of regional shallow landslide hazard considering the characteristics of real-time rainfall and landslide intensity, and completes the evaluation of shallow landslide hazard in typical urban area of Wuling Mountain. The research results have important theoretical and practical significance in enriching and perfecting the existing rainfall-induced landslide prediction and evaluation models and methods, promoting technological progress of landslide hazard analysis, and guiding the control and monitoring of shallow landslide disaster.

降雨引发的浅层滑坡具有区域性的群发效应，能够在短时间内造成大量的灾难性损失。降雨过程的动态性及多样性直接影响着滑坡发生的位置及强度。本项目从降雨对浅层滑坡演化过程的作用机理入手，将滑坡的地质机理和变形失稳过程考虑到滑坡危险性评价的研究中，确定区域浅层滑坡灾害强度量化方法，在武陵山区滑坡灾害调查数据统计分析的基础上，建立土体结构的概化模型，分析不同土体结构模型的入渗特征，研究坡体不同部位的及其相邻坡体坡体之间的雨水运动规律；进行室内物理模型试验，构建降雨入渗条件下浅层滑坡的力学计算模型，提出浅层滑坡变形失稳过程中滑坡强度的量化表达形式；建立考虑实时降雨特征及滑坡强度的区域浅层滑坡危险性动态预测方法，完成武陵山区典型城镇浅层滑坡灾害的危险性评价。研究成果在丰富、完善和发展现有降雨诱发滑坡预测与评价模型及方法、促进滑坡灾害风险分析技术进步、指导浅层滑坡灾害治理和监测方面具有重要的理论及现实意义。

降雨引发的浅层滑坡具有区域性的群发效应，能够在短时间内造成大量的灾难性损失。降雨过程的动态性及多样性直接影响着滑坡发生的位置及强度。本项目聚焦于武陵山区湘西北浅层滑坡灾害，初步揭示了武陵山区湘西北地区浅层滑坡的分布特征及发育规律；分析了典型浅层土体的微观特征及其结构概化特征，进行了典型土体模型的室内外入渗及径流实验，得到了浅层土体概化模型入渗特征及其雨水运动规律；通过对典型降雨型滑坡的变形机制及稳定性分析，并结合降雨型滑坡地质力学模型室内试验，初步建立了考虑不同降雨过程的区域滑坡灾害稳定性计算模型；开展了多组降雨条件下浅层滑坡地质力学模型运动过程模拟实验，初步建立了降雨型浅层滑坡的滑坡强度定量分析模型。在以上研究基础上，研究提出了一种降雨型浅层滑坡的危险性动态预测方法，实现了降雨诱发浅层滑坡灾害的区域危险性动态预测，为研究区滑坡风险评价提供技术支撑。