废弃煤矿结构演化与水系调整规律研究

After the coal mine discarded, the structure evolution and water system adjustment of coal mine stratums could not stopped . The project will combine of research methods on investigating in situ, theoretic analysis，numerical simulation，test researching,application in situ as well as the synthesis analyzing. Study on the coal mins region stratums structure, structural characteristics of the coal mine,set up the boundary conditions between the abandoned coal mine structure and the aquifer, impermeable layer, and water supply,Measuring from abandoned mines of rock specimen tensile creep rupture degree, compression creep density as well as permeability coefficient with time variation by the laboratory equipment. Establish the rock specimen tensile creep rupture - compression creep dense model, pore-fracture seepage constitutive equation, as well as the rock specimen tensile creep rupture criterion. Set up the stratigraphic structure deformation rheological - rupture mathematical model, rupture - compacting process water flow mathematical model in the caving zone as well as deformation - failure - coupled mathematical model of fracture seepage. By introduction of the isotropic element, non-coordination equivalent element between the different elements, and dynamic destruction element . carry out the solving by the finite element method , and develop of calculation program. Apply in abandoned coal mine just as Fuxin, Liaoyuao, Fushun as well as Shuangyashan, analysis the reason of the abandoned mine structure evolution and water loss , natural recovery causes by surface water and groundwater. Set up the treatment optimization program for abandoned mine structure evolution and water loss as well as surface ponding.

煤矿废弃后，矿井地层结构演化与水系调整并没有停止。项目采用现场考察、理论分析、数值模拟、实验研究、现场应用和综合分析相结合的研究方法，研究废弃煤矿区域地层结构、矿井结构特征，建立废弃煤矿矿井结构与含水层、隔水层及水源补给边界条件。采用自制实验设备，实测废弃煤矿岩石试件拉张蠕变破裂度、压缩蠕变密实度及其渗透系数随时间变化规律；建立岩石试件拉张蠕变破裂-压缩蠕变密实模型、孔隙-裂隙渗流本构方程以及岩石试件拉张蠕变破裂判据。建立地层结构变形-破裂的流变数学模型、冒落带破裂-密实过程的水渗流数学模型以及变形-破裂-裂隙渗流的耦合数学模型；引入单元内各向同性、单元间非协调等效单元和动态破坏单元，进行有限元法求解，开发计算程序。在阜新、辽源、抚顺及双鸭山等废弃煤矿现场应用，分析废弃矿井结构演化规律与水资源流失、地表积水与地下水自然恢复成因。提出废弃矿井结构演化与水资源流失、地表积水治理优化方案。

煤矿废弃后，矿井地层结构演化与水系调整并没有停止。项目自制实验设备进行岩石拉张蠕变实验及冲击扰动下圆盘试件拉张蠕变实验；引入数字图像测量技术，开发了基于数字图像的岩石三轴应力渗流温度蠕变耦合试验系统，测定温度、应力对煤岩渗透率的影响，煤样的渗透率随着围压增加而降低，风干煤样和束缚水煤样具有明显的滑脱效应，饱和煤样没有滑脱效应，随着含水率增加，煤样的渗透率降低，饱和煤样的渗透率随着孔压增加而增长，随着温度升高，煤颗粒膨胀，空隙空间变小，不利于瓦斯流动，渗透率降低，另一方面，瓦斯的运动速度增加，粘性降低，使得宏观渗透率升高，随着加卸载次数增加，煤样的渗透率增加，但增长速率逐渐趋缓；基于留小煤柱开采采场上覆岩层破坏规律的研究，对顶板岩层力学模型进行了受力分析，总结了顶板岩层离层破坏的基本条件，并分析了煤柱破坏失稳方式；通过相似材料模拟实验，分析了浅伏煤层开采后采空区上覆岩层变形破坏特征；通过岩石试件单轴抗压强度实验，对岩石弹性模量与抗压强度的关系式进行了验证，推导岩体弹性模量与含水量的关系式；岩石的抗压强度随含水率的增加而降低，但水对不同类型的岩石影响程度不一样，对坚硬岩石强度影响较小，而对软弱岩石影响较大；试验测定岩石密度、阻尼比、阻尼系数与含水量的关系，岩石密度随含水量的增加而增大，阻尼比随含水量的增加而递减，阻尼系数随含水量的增加而增大，且岩石密度、阻尼比和阻尼系数均是含水量的函数；将采空区上覆顶板岩层和支撑桩柱体看成一个系统建立力学模型，从整体上对其进行分析研究。利用已推导出的岩体弹性模量与水的函数关系式，推导出采空区系统在水的作用下的总势能函数，利用尖点突变理论得出系统突变失稳的充要力学条件，分析了水对系统破坏失稳机理和稳定性的影响。