煤矿地下水库储水结构时空演化机理研究

Project of storing and utilizing mine water by coal mine underground reservoir has effectively alleviated the water resource shortage problem of the ecologically fragile area in Chinese western region. However, the phenomenon of water storage structure variation were occurring during reservoir long-running, which not only influenced water storage capacity and ground surface subsidence of reservoir, but also easily induced reservoir water inrush and seriously threatened the mine safety. Therefore, based on multi-disciplinary crossing and multi-field coupling theories, the deformation response of water storage structure in coal mine underground reservoir under a interrelationship between mining disturbance and coupling effect of water will be systematically researched. According to mechanical and hydro-physical properties of water storage rock, similar material rock will be made. And similar material modeling test bed considering fluid-solid coupling will be improved, then constitutive model of the rock mass deformation under the coupling effect of stress-permeability-chemical will be build. With the similarity test and numerical simulation, the stress field, seepage field and chemical field distribution laws of water storage structure in coal mine underground reservoir are about to be analyzed. Also, the spatial distribution and time variation characteristics of water storage structure in coal mine underground reservoir are going to be explored. Then spatiotemporal evolution mechanism of water storage structure in coal mine underground reservoir shall be revealed. At last, the spatiotemporal evolution prediction model of water storage structure in coal mine underground reservoir and its numerical algorithm will be proposed. The research results will provide theoretical basis for water storage capacity and ground surface subsidence predictions of coal mine underground reservoir, which will largely ensure the safe production of coal mine where there are many underground reservoirs.

煤矿地下水库储用矿井水工程有效缓解了我国西部生态脆弱矿区水资源短缺问题，然而在水库长期运营期间出现的储水结构变异现象不仅影响水库储水能力和地表沉陷，而且极易诱发水库突水，严重威胁矿井安全。为此，本项目基于多学科交叉和多场耦合理论对开采扰动与水耦合效应相互作用下的煤矿地下水库储水结构变形响应展开系统研究。结合煤矿地下水库储水岩体力学、水理性质，制备储水岩体相似材料岩块，改进流固耦合相似材料模型试验台，构建应力-渗流-化学耦合作用下岩体变形本构模型。通过相似试验和数值模拟分析水岩-采动作用下煤矿地下水库储水结构应力场、渗流场、化学场分布规律，探究煤矿地下水库储水结构空间分布特征和时间变化特性，揭示煤矿地下水库储水结构时空演化机理，提出煤矿地下水库储水结构时空演化预测模型并开发数值解法及计算程序，为煤矿地下水库储水量及地表沉降量预测提供基础理论依据，也极大程度地保障了煤矿地下水库矿井的安全生产。

近年来，随着我国西部生态脆弱矿区大力推进煤矿地下水库工程建设，有效缓解了矿区水资源短缺问题。但在煤矿地下水库长期运营过程中，水岩-应力作用下储水结构变形失稳却给矿井安全生产造成了严重威胁。为此，项目选取神东矿区大柳塔煤矿拟建地下水库22616工作面为工程背景，采用室内实验、数值模拟、现场监测与理论分析相结合的方法对水岩-应力作用下煤矿地下水库储水结构时空演变机理展开了深入、系统研究。基于煤矿地下水库岩体常规加载变形实验，确定了煤矿地下水库岩体应力与碎胀系数间的函数关系。根据相似实验和数值计算结果，构建了煤矿地下水库走向和倾向覆岩结构力学模型，划分了煤矿地下水库岩体应力分区，推导出各分区岩体应力空间变化数学方程。结合煤矿地下水库岩体应力与碎胀系数的相关性，界定了煤矿地下水库岩体碎胀特性分区，建立了煤矿地下水库储水空隙空间分布数学模型。同时，通过煤矿地下水库岩体恒载压缩变形实验，明确了煤矿地下水库岩体空隙率与时间关联度，揭示了煤矿地下水库储水结构时空演变特性。提出了煤矿地下水库储水系数动态预测模型，并利用自主研制的煤矿地下水库储水系数测定实验装置对模型可靠性进行了验证。研究成果为煤矿地下水库库容设计提供了重要的科学依据，保障了煤矿地下水库的安全、高效运营，推动了我国西部生态脆弱矿区绿色开采进程。