关闭矿井地下水位回升环境下地表残余变形演变机理与预计模型研究

Surface residual deformation is the primary problem in the development and utilization of abandoned land resources in closed mines. After the groundwater level rising in closed mines, the surface residual deformation shows a coupling result of subsidence and uplift. While the existing prediction methods do not fully consider the above fact, and they are difficult to accurately predict deformation. In view of this, this project takes the construction of prediction model of surface residual deformation considering the groundwater level rising as the research object. The mechanical test, equivalent material simulating, numerical simulation, numerical simulation and field measurements verification are adopted to study the contents as follows: 1) The strength attenuation and volume expansion of saturated coal and rock are analyzed, and the constitutive model of saturated coal and rock softening and expansion is established. 2) The origin and transmission of surface residual deformation induced by the groundwater level rising are studied, and its evolution mechanism is revealed. 3) The calculation methods of subsidence and uplift are established respectively. The prediction model of surface residual deformation of closed mines is constructed considering coupling relationship among the process of groundwater level rising, surface subsidence and uplift, and the corresponding parameter system and parameter inversion method are put forward. The research results can provide scientific support for the development and utilization of abandoned land resources in closed mine. Therefore, it has certain scientific significance and application value.

地表残余变形是关闭矿井废弃土地资源开发利用所面临的首要问题。关闭矿井地下水位回升后，地表残余变形表现为沉降与抬升的耦合结果，而现有预计方法未能充分考虑上述事实，难以实现对其精准预计。针对于此，本项目以构建顾及地下水位回升的关闭矿井地表残余变形预计模型为研究对象，综合采用力学测试、相似材料模拟、数值模拟、理论分析和实测验证等方法，主要研究以下几点内容：1）分析煤岩饱水后的强度衰减与体积膨胀变化，建立煤岩饱水软化膨胀本构模型；2）研究地下水位回升诱致地表残余变形的起源与传递变化过程，揭示其演变机理；3）分别建立沉降与抬升的计算方法，顾及地下水位回升进程、残余沉降与地表抬升三者间的耦合关系，构建关闭矿井地表残余变形预计模型，并提出与之配套的参数体系与参数反演方法。本项目的研究成果可为关闭矿井废弃土地资源开发利用提供科学支撑，因此，具有一定的科学意义和应用价值。

再利用关闭矿井呆滞土地资源对于促进资源枯竭型城市经济转型与可持续发展意义重大。本项目瞄准影响关闭矿井土地资源有效再利用的地表残余变形问题，综合采用室内实验、数值模拟、现场勘测和理论分析等研究方法，首先，揭示了关闭矿井覆岩结构赋存特征，通过分析破碎煤岩体的变形特性建立了破碎煤岩体的本构模型，构建了关闭矿井覆岩结构多元介质力学模型；其次，利用不同时段多源SAR数据和时序InSAR技术提出了适用于关闭矿井地表残余变形长时序监测方法，研究了淮南矿区和郑州矿区关闭矿井残余变形特征，分析了关闭矿井地表沉降与抬升的时序变化特征，总结出关闭矿井地表残余变形基本存在下沉、稳定和抬升阶段，但三个阶段并非随时间逐次发生，这与水文地质采矿条件密切相关；再次，结合关闭矿井覆岩结构特征揭示了地表残余变形演变机理，在地下水位回升后，关闭矿井地表沉降主要来源于破碎岩体压密、边界空洞压密和覆岩离层间的压密，而关闭矿井地表抬升主要来源于破碎岩体弹性恢复变形、松散层弹性恢复变形和膨胀岩的轴向膨胀；从次，构建了关闭矿井地表残余变形预测模型与参数体系，分别基于改进乌鸦搜索算法和鲸鱼优化算法给出了预测模型参数反演方法；最后，建立了关闭矿井建设场地稳定性评判体系，采用定性和定量相结合的方法筛选评价指标，利用主成分-信息熵相结合方法证明指标体系的合理性，基于最小鉴别信息融合主观权重和客观权重给出评价指标的综合权重，利用梯形云模型评价关闭矿井建设场地稳定性。项目研究成果获中国测绘学会测绘科学技术奖一等奖1项、中国煤炭工业协会科技奖二等奖1项、安徽省科学技术奖三等奖1项，发表学术论文15篇（SCI收录6篇），申请发明专利4件（授权1件、实审3件），申请软件著作权2项，授权1项，培养硕士研究生2人、联合培养博士研究生1人，申请人入选第八届中国科协青年人才托举工程。