关闭矿井地表沉陷机理、规律及预测方法研究

The closed mines are a large number and widely distributed in our country. Their collapse are hidden, long-term and harmful and can bring a serious threat to people's life and property. It has important theoretical and practical significance to study the surface subsidence prediction and risk assessment methods for closure mine. By means of geological and mining data collection, in-situ measure, laboratory test and computer simulation analysis, this project plans to study the multi-source subsidence information acquisition and fusion methods to acquire reliable subsidence data of the closed mines; and then combining the mechanical test of cracked rock mass and the action of underground water in closed mines, to study the characteristics and deformation mechanism of mining overburden strata structure, the laws and prediction method of surface subsidence, risk evaluation and risk regionalization method of subsidence hazards etc., to reveal the mechanism and laws of overburden strata movement and ground surface subsidence in closed mines; finally, to construct subsidence prediction methods and corresponding parameter system, and to establish subsidence risk evaluation and risk regionalization methods for closed mines, so that current subsidence theory can be improved and can provide better theoretical and technical supports on the subsidence risk prevention and control of closed mine.

我国关闭矿井量大面广，其塌陷具有隐蔽性、长期性和危害性，给人民生命财产带来严重威胁。研究关闭矿井地表沉陷预测方法及风险性评价方法具有重要的理论和实际意义。本项目拟通过收集地质采矿资料、现场实测、室内试验和计算机模拟分析，在研究地表沉陷多源信息获取方法基础上，获取可靠的关闭矿井地表沉陷资料，结合破裂岩体力学试验，深入研究地下水胁迫作用下，关闭矿井采动覆岩结构特征与变形机理、地表沉陷规律与预测方法、地表沉陷灾害风险性评估及区划方法等，明确关闭矿井采动覆岩及地表沉陷机理和规律；建立关闭矿井地表沉陷预测方法及预测参数体系，构建关闭矿井地表沉陷风险性评估及区划方法，完善现有的开采沉陷理论，为关闭矿井地表沉陷风险防控提供理论和技术支撑。

我国关闭矿井量大面广，其塌陷具有隐蔽性、长期性和危害性，严重威胁关闭矿井上方及周边的建构筑物、交通基础设施等的安全，研究关闭矿井地表沉陷预测方法及风险性评价方法具有重要的理论和实际意义。本项目以徐州东西部关闭矿井为主要研究对象，通过现场实测、理论分析，取得的主要成果为：（1）划分了采动覆岩结构类型，分析了采动破裂岩体、覆岩结构及松散层、膨胀岩体变形机理，明确了关闭矿井次生沉陷源；（2）开展SAR影像滤波、DS点识别与优化、大梯度形变信息InSAR获取等的研究，取得了系列成果，初步解决SAR影像噪声与关闭矿井沉陷信息难以分离、大梯度形变信息难以提取及非城区相干点少的问题，为采用InSAR技术获取关闭矿井准确、完整的次生沉陷信息提供了技术方法；（3）基于徐州东西部矿区地面实测和10年InSAR监测的地面沉陷信息，分析研究了关闭矿井次生沉陷时空变化规律，明确了关闭矿井次生沉陷分为五个阶段（稳定-下沉-相对稳定-上升-稳定）及与地质采矿条件的关系，深入分析研究了多煤层开采下煤层上升和上煤层下沉的叠加效应；（4）基于采动破裂岩体本构关系、岩土力学、开采沉陷学等，分别构建了单一煤层和多煤层长壁全陷法开采、充填开采和柱式开采覆岩与地表下沉和上升预测模型和参数选取方法；给出了冲积层回弹及膨胀岩膨胀引起的覆岩与地表上升预测模型，通过徐州矿区关闭矿井地面和InSAR监测资料证明了方法的可靠性和精度；（5）将关闭矿井地面分为危险性小、危险性中、危险性大三类，重点研究了长壁全陷法开采区、柱式开采区地表风险评价方法。结合不同保护对象损害评定指标，分别给出了不同保护对象分级评定方法和区划方法。对于柱式开采区，基于煤柱剥离思想，研究了煤柱剥离量与煤柱高度的关系，建立了煤柱强度与煤柱剥离的关系式，由此构建了条带开采、房柱开采煤柱长期稳定性评价方法。上述成果为关闭矿井覆岩及地表次生沉陷预测和风险评价奠定了理论基础，是对现有开采沉陷理论的补充和完善。