复合坚硬顶板水压裂缝扩展过程研究

发布时间：2019-03-21 08:39

【摘要】：为研究复合坚硬顶板的水压裂缝扩展过程,建立相应扩展模型,对水压裂缝的扩展机制和扩展模式进行理论分析,以大同矿区复合坚硬顶板为研究对象,采用岩石损伤破裂过程渗流-应力耦合分析系统(RFPA~(2D)-Flow)数值模拟软件,研究水压裂缝的扩展过程及不同因素下的影响,并用相似模型试验方法验证数值模拟结果。结果表明,水压裂缝的扩展主要受到顶板岩石的力学性质、主应力差、层理面倾角和层理面力学性质等因素的影响。大同矿区的复合坚硬顶板中的水压裂缝优先扩展进入强度最低的泥岩层,随主应力差增大,水压裂缝向不同岩性岩层扩展过程的差异性减弱。随着层理面倾角增大,水压裂缝由穿过粗粒砂岩层扩展逐渐转为沿层理面和限制在压裂层内扩展。而层理面弹性模量的增大,有利于水压裂缝直接扩展进入粗粒砂岩层。
[Abstract]:In order to study the propagation process of water pressure crack of composite hard roof, establish the corresponding expansion model, analyze the propagation mechanism and mode of water pressure crack theoretically, and take the compound hard roof of Datong mining area as the research object. The seepage-stress coupling analysis system (RFPA~ (2D)-Flow) is used to study the propagation process of water pressure fracture and the influence of different factors. The numerical simulation results are verified by similar model test method. The results show that the propagation of water pressure cracks is mainly influenced by the mechanical properties of the roof rock, the difference of principal stress, the inclination of the bedding surface and the mechanical properties of the bedding surface. The water pressure fracture in the composite hard roof of Datong mining area first extends into the mudstone with the lowest strength. With the increase of the principal stress difference, the difference of the propagation process of the water pressure fracture to different lithologic strata weakens. With the increase of the dip angle of the bedding surface, the water pressure fracture gradually changes from spreading through the coarse sandstone layer to spreading along the bedding surface and confined to the fracturing layer. The increase of elastic modulus of the bedding surface is beneficial to the direct extension of the water pressure fracture into the coarse sandstone layer.
【作者单位】：重庆大学煤矿灾害动力学与控制国家重点实验室;大同煤矿集团有限责任公司;中煤科工集团重庆研究院有限公司;
【基金】：中国博士后科学基金资助(2016M602655) 长江学者和创新团队发展计划项目(IRT13043)
【分类号】：TD327.2

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