我国关闭矿井数量多范围广，矿井关闭后，停止排水，地下水位上升，受地下水影响，覆岩及地表将再次沉陷，危及关闭矿井上方和周边建构筑物、交通电力通讯等基础设施安全及建设场地稳定性，研究关闭矿井覆岩与地表次生沉陷机理、规律、预测方法具有重要的理论和实用价值。在收集国内外相关文献基础上，结合徐州东西部矿区关闭矿井地面次生沉陷监测实践，系统回顾和分析了关闭矿井地面次生沉陷监测方法、形成机理、时空分布规律及预测方法研究现状和存在的问题。首先，对比研究了常规地面变形监测方法和航天航空测量方法的优缺点，重点总结了合成孔径雷达干涉测量（InSAR）技术应用于关闭矿井地表沉陷监测中的优势及存在的问题；其次，基于国内外大量实测资料，分析总结了关闭矿井覆岩及地表次生沉陷形成机理及时空演化规律，得到了覆岩及地表下沉的主要诱因为采动破裂岩体、覆岩结构及煤（岩）柱在地下水作用下的变形或失稳；覆岩与地表上升的主要诱因为：随着地下水位升高，作用在采动破裂岩体、第四系松散层内的孔隙压力增大，有效应力减小，使其产生弹性恢复变形，膨胀岩体遇水膨胀也可能导致覆岩及地表上升；关闭矿井次生沉陷在时间上可分为5个阶段：①初期稳定阶段；②下沉阶段；③中间稳定阶段；④上升阶段；⑤最终稳定阶段。并分析了不同开采方法、多煤层开采对关闭矿井地表沉陷时空分布规律的影响。在此基础上，基于采动破裂岩体本构关系，分下沉和上升2阶段，分别给出了长壁垮落法、充填开采和柱式开采地表沉陷预测模型。最后指出，关闭矿井覆岩及地表沉陷机理、规律是非常复杂的物理力学过程，涉及地质采矿环境、采动破裂岩体及覆岩结构、本构关系、变形特征、水岩耦合作用、地下水动力效应、膨胀岩体膨胀变形等复杂因素，因此，还需进一步深入研究。

The closed mines are a large number and widely distributed in our country. After the mine is closed,the drainage will be stopped and the groundwater level will rise. Affected by the groundwater,the overburden and surface will sink again,endangering the safety of buildings,traffic,power,communication,and other infrastructure,and the stability of the construction site above and around the closed mine. Therefore,studying the mechanism,law and the prediction method of surface secondary subsidence in closed mine has important theoretical and practical significance. Based on the collection of relevant literature at home and abroad,combined with the monitoring results of surface secondary subsidence of closed mines in the eastern and western mining areas of Xuzhou,this paper systematically reviews and analyzes the research status and existing issues of monitoring methods,formation mechanism,temporal-spatial distribution law,and predic〖LM〗tion methods of surface secondary subsidence of closed mines. Firstly,the advantages and disadvantages of conventional ground deformation monitoring methods and aerospace measurement methods are compared,and the superiority and defect of

Interferometic synthetic Aperture Radar(InSAR)technology in surface subsidence monitoring of closed mines are summarized; Secondly,based on a large number of measured data at home and abroad,the formation mechanism and temporal-spatial evolution law of overburden and surface secondary subsidence in closed mines are analyzed and summarized,the main inducing factors of overburden and surface subsidence are obtained,which are the deformation or instability of mining fractured rock mass,overburden structure and coal (rock)pillar under the action of groundwater; The main inducements of overburden and surface uplift are that with the rise of groundwater level,the pore pressure acting on mining fractured rock mass and Quaternary loose layer increases,and the effective stress decreases,resulting in elastic recovery deformation,and the expansion of swelling rock mass in groundwater may also lead to overburden and surface uplift; The secondary subsidence of closed mine can be divided into five stages in time:①initial stable stage;②subsidence stage;③intermediate stable stage;④uplift stage;⑤final stable stage,and the influence of different mining methods and multi coal seam mining on the temporal-spatial distribution law of surface subsidence of closed mines is analyzed. On this basis,based on the constitutive relationship of mining fractured rock mass,the prediction models of surface subsidence and uplift of longwall caving mining,filling mining,and pillar mining are given respectively. Finally,we point out that the mechanism and law of overburden and surface subsidence of closed mine are very complex physical and mechanical processes,involving geological mining environment,mining fractured rock mass and overburden structure,constitutive relationship,deformation characteristics,water-rock coupling,groundwater dynamic effect,expansion deformation of swelling rock mass and other factors. The current research is preliminary,therefore,further research is needed.