沙基胶结充填防治柱式采空区顶板灾害机理研究

In the western mining area of China, there exist a large number of coal pillar goaf. After long-term weakening effects such as creep and weathering, the instability of the coal pillar group in goaf causes the roof of the goaf to suddenly collapse in a large area, resulting in the earthquake, goaf hurricanes, sudden surface subsidences, landslides and mudslides, and its derived geological disasters, which threaten the safety of mining areas and restrict the coordinated development of coal resources and ecological environment. Aimed at the mechanism and prevention method of the roof disaster in pillar goaf of the western mining area, based on site investigation, theoretical analysis, laboratory test, similar simulation, numerical calculation and field measurement, this project will analyze the interlocking failure mechanism of damaged coal pillar group and roof, revealing the disaster-causing mechanism and the control keys of pillar goaf roof. Besides, the physical and mechanical properties, time relationship characterization of sand-based cemented backfill body will be tested, the mechanical model of synergistic deformation of coal pillar group-backfill body-roof will be established, the long-term stability of the surrounding rock under the conditions of backfilling goaf or replacing coal pillars with backfill body will be analyzed. Finally, the preventing and controlling method of pillar goaf roof disasters will be formed, which will provide theoretical and technical support for prevention and treatment of roof disaster in goaf, and also provide important scientific basis for safe mining in western mining area.

我国西部矿区存在大范围的柱式采空区，经过长期蠕变、风化等弱化作用，采空区内煤柱群发生失稳造成采空区顶板突然大面积冒落，引发矿区地震、采空区飓风、地表突然塌陷、山体崩塌、滑坡及泥石流等顶板灾害及其衍生地质灾害，严重威胁矿区安全，制约煤炭资源与生态环境的协调发展；本项目针对西部矿区柱式采空区顶板灾害发生机理及防治方法，采用现场调研、理论分析、实验室测试、相似模拟、数值计算及现场实测的综合研究方法，研究损伤型煤柱群及顶板连锁失稳机制，揭示柱式采空区顶板灾害的致灾机理及其控制关键，测试沙基型胶结充填体物理力学特性及其时间相关特性，建立煤柱群-充填体-顶板协同变形力学模型，分析充填加固或者替代煤柱条件下围岩的长期稳定性，最终形成不同柱式采空区顶板灾害的充填防治方法，将为柱式采空区顶板灾害的防治提供理论及技术支撑，也为西部矿区煤炭的安全开采提供重要的科学依据。

我国西部矿区存在大范围的柱式采空区，经过长期蠕变、风化等弱化作用，采空区内煤柱群发生失稳造成采空区顶板突然大面积冒落，引发矿区地震、采空区飓风、地表突然塌陷等顶板灾害，严重威胁矿区安全，制约煤炭资源与生态环境的协调发展。因此，形成柱式采空区顶板灾害的充填防治方法，为柱式采空区顶板灾害的防治提供理论及技术支撑，对于西部矿区煤炭的安全开采具有重要意义。.本项目针对西部矿区柱式采空区顶板灾害问题，密切围绕柱式采空区顶板灾害发生机理及其防治方法两大主题，采用现场调研、理论分析、实验室测试、相似模拟及现场实测的综合研究方法，在采空区煤柱群失稳机理、采空区煤柱群与顶板协同变形力学行为、沙基胶结充填体力学特性及稳定性、充填条件下煤柱群与顶板长期稳定性等方面取得了突破：（1）揭示单个煤柱在长期蠕变损伤下强度弱化机制，研究损伤型煤柱群及顶板由点至面的失稳规律，得出柱式采空区顶板灾害灾变因子及控制关键；（2）分析柱式采空区煤柱群与顶板协同变形规律，建立了柱式采空区围岩失稳灾变力学模型，研究了柱式采空区顶板灾害的诱发关键及控制；（3）分析控制煤柱群与顶板稳定时胶结充填体的性能要求，测试沙基胶结充填体物理力学性能及长期稳定性，建立沙基胶结充填体时间-应力-应变关系；（4）构建煤柱群-充填体-顶板协同变形力学模型，研究不同充填条件下煤柱群及顶板的稳定性，最终提出不同条件柱式采空区顶板灾害的充填防治方法。.研究成果获得中国煤炭工业协会科技进步一等奖1项、二等奖1项，发表学术论文15篇（SCI收录14篇，EI收录1篇），获授权国外发明专利6项、国内发明专利4项，参与制定国家标准1项，培养青年骨干教师1名，博士研究生1名，硕士研究生7名，参与了2项学术会议。本项目的研究为防治西部矿区柱式采空区顶板灾害提供基础理论支撑，并进一步丰富了防治遗留煤柱采空区灾害治理技术及其理论体系。