采动影响下晋西原状黄土结构性演化规律研究

The structural natural loess, formed by under consolidated, unsaturated and loose granular medium, is widely distributed in Western Shanxi and Hedong coalfield. It is easy to form soil landslide, soil and water loss, vegetation degradation and destruction of the ecological environment caused by underground coal mining. To explore the formation mechanism of loess landslide in mining, this project focuses on the structural evolution of loess in the mining area. The main contents include: (A) Investigation and analysis of the basic characteristics of loess distribution and characteristics of the destruction in Western Shanxi. (B) Study on the relationship between the deformation degree of the Loess and the mining conditions, the topography in the western Shanxi by measurement analysis, numerical simulation. (C) The structural evolution of loess in the process of mining was studied by three axial compression and SEM. (D) Through theoretical analysis, study on the relationship between loess ground movement and structural evolution of loess under the influence of mining, and construct a structural parameters calculation model of disturbed loess, which takes surface movement and deformation and the key elements of loess geological and mining as the variables. The purpose of this project is to construct the prediction model of surface movement and deformation of underground coal seam in the loess area of Western Shanxi, and reveal the mechanism and regularity of loess structural evolution in the process of mining. It can provide the theoretical basis for the stability analysis of the loess slope and the prediction of the landslide, and provide technical support for ecological environment protection in mining area of Loess covered.

山西西部与河东煤田广泛分布由欠固结非饱和的松散颗粒介质组成、具有结构性的天然黄土，在采动诱导下易于形成土体滑坡、水土流失、植被退化等破坏生态环境现象。为探究采动黄土滑坡产生的机理，本项目围绕采动区黄土结构性演化的问题开展研究。主要内容包括：①调查分析晋西黄土分布的基本特点和地貌破坏的特征；②通过实测分析、数值模拟，确定采动过程中晋西黄土的变形程度与开采条件、地形地貌的关系；③采用三轴压缩、扫描电镜试验，研究采动过程中黄土结构性演化规律；④通过理论分析，研究采动影响下晋西黄土的地表移动与黄土结构性演化状况之间的关系，构建以地表移动变形及关键地质采矿要素为变量的扰动黄土结构性参数计算模型。本项目旨在构建晋西黄土区域地下煤层开采地表移动变形的预测模型，揭示采动过程中该区域黄土结构性演化机理及规律，为采动黄土坡体的稳定性分析及滑坡预测提供理论基础，为黄土覆盖矿区的生态环境保护提供技术支持。

山西西部与河东煤田广泛分布由欠固结非饱和的松散颗粒介质组成、具有结构性的天然黄土，在采动诱导下易于形成土体滑坡、水土流失、植被退化等破坏生态环境现象。为探究采动黄土滑坡产生的机理，本项目围绕采动区黄土结构性演化的问题开展研究①针对山西省黄土丘陵区采煤地面损害进行了调查，确定了采煤沉陷区生态环境破坏的类型，通过分析山西省六大煤田的采动地面裂缝分布特征，确定了采动地面裂缝影响因素：黄土和砂岩在开采深度中的比例、岩石厚度与开采厚度的比例和地面坡度。②针对黄土丘陵矿区采动地面损害的监测问题，采用三维激光扫描技术、DInSAR技术、无人机低空遥感技术、GNSS监测技术对采动地面损害程度进行了全方位多尺度的定量分析。③研究了晋西超固结黄土与固结黄土的力学性质，重点分析黄土的结构特性及两类黄土的构度，确定了超固结黄土与正常固结黄土的结构性参数。④研究了采动黄土结构演化机理，采用数值模拟软件对采动过程中裂缝发育的规律进行了研究，构建了采动程度与裂缝宽度、深度的关系模型，从而为黄土丘陵区采动地面损害的定量评价提供了理论支持。