甘肃省不同类型黄土滑坡的滑动致灾空间预测研究

Different types of loess landslide have very different sliding distance. If the sliding distance is short, then the hazard range is small. If the sliding distance is long, then the hazard range is big. This project take loess landslide in Gansu as object of study, based on fully collecting and analyzing and summarizing the results of previous studies, investigate and survey and mapping the typical loess landslide. The characteristics of the development and distribution and sliding and deformation and failure of loess landslides are found out. Thorough analysis and summarizing of the characteristics of loess landslides, further improve a generalized loess landslide concept and the classification scheme of loess landslides. Through the statistical analysis of the basic characteristic parameters of the different types of loess landslides, build the statistical model of sliding distance forecasting of loess landslide. The various strength characteristics of sliding zone soil of loess landslide are systemic analyzed and summarized. The disaster-causing mechanism and the geomechanics mechanism of various types of loess landslides well are explored. The kinematics model of sliding distance forecasting of loess landslide are established. This research will supply and improve theory and practice level of the classification of loess landslide and sliding distance and hazard range forecasting of loess landslide. It well provides a scientific basis and technological support for geological disaster prevention and management decision-making departments to reasonably determine the loess landslide hazard range. For effectively avoiding the landslide risks to protect people's lives and property, has a high academic value and realistical significance.

不同类型的黄土滑坡滑动距离差异很大。滑坡滑动距离短，则致灾范围小；滑坡滑动距离长，则致灾范围大。 本项目以甘肃省黄土滑坡为研究对象，在充分收集整理和分析总结前人研究成果的基础上，对典型的黄土滑坡进行现场调查和勘察测绘，查明黄土滑坡的发育分布、滑动和变形破坏等特征，深入分析和归纳总结黄土滑坡的特性，进一步完善广义黄土滑坡概念和黄土滑坡的分类方案。对不同类型黄土滑坡的基本特征参数进行统计分析，构建黄土滑坡滑距预测的统计模型；系统分析和归纳总结黄土滑坡滑带土的强度特性，探寻不同类型黄土滑坡的成灾机理和地质力学机制，建立滑坡滑距预测的运动学模型。 本研究成果将补充和完善黄土滑坡分类、滑坡滑距和致灾范围预测研究的理论与实践水平，为地质灾害防治与管理决策部门合理确定黄土滑坡致灾范围提供科学依据和技术支撑，具有较高的学术价值和现实意义。

本项目在调查分析甘肃省典型黄土滑坡发育分布特征的基础上，补充完善了黄土滑坡的分类。通过室内岩土试验分析，研究了黄土滑坡滑带土工程地质性质。通过滑坡典型案例的调查分析，继续深入探讨不同类型黄土滑坡机理与活动致灾特征。合理选取典型黄土滑坡滑动距离预测的特征参数，建立黄土滑坡的滑距预测模型。采用基于连续介质力学的离散元方法（CDEM），对典型黄土滑坡的运动过程进行数值仿真分析。得到以下研究成果：.（1）补充完善黄土滑坡分类，提出“泥流型黄土滑坡”类型。首先对甘肃省境内广泛发育的黄土滑坡进行了详细的分类研究，在原有4种类型的基础上，提出了另一种典型的黄土滑坡类型，即泥流型黄土滑坡，该类黄土滑坡近年来在甘肃省境内广泛发育。.（2）通过理论分析和现场试验观测分析，提出了“饱和黄土滑坡形成中的侧压力作用”。以甘肃省黑方台地区黄土层内滑坡为例，灌溉水大量入渗在黄土层底部形成饱和软弱基座，在斜坡后部饱和黄土层中产生较大的侧压力，水平作用于前部斜坡体，助推其变形破坏和高速启程滑动，也是区内饱和黄土滑坡形成的动力来源之一。.（3）通过对陇中黄土高原典型地区（天水市）滑坡特征的区域性研究，进一步补充和验证了“天水市中型以上黄土滑坡的平均坡度仅为10°～15°”，为国家相关规范的编制提供了有力技术支撑和借鉴。.（4）基于经典运动物理学和能量守恒定律，提出“基于能量折减的质点运动学滑坡滑距预测方法”。该研究将滑坡运动概化为质点运动，引入综合能量折减系数η和“L比”，推导出滑距预测模型。该成果为黄土滑坡滑距预测提供了一种简单、适用的方法。.（5）基于CDEM的洒勒山滑坡过程模拟研究。利用CDEM力学计算软件，对洒勒山高速远程滑坡过程进行模拟，研究由蠕变导致的下部老滑坡复活并带动上部滑体滑动的滑坡整体运动过程，并对上下部滑体及监测点的位移、速度、加速度等进行分析。模拟得到的滑坡过程与实际情况基本吻合。