保水采煤的隔水关键层理论与应用研究

Study on the Theory and Application of Water-resisting Key Strata on Water-preserved Mining

针对矿区生态环境保护,资源和环境协调开发的可持续发展观,保水采煤思想应运而生.为实现保水采煤这一重要主题,提出了隔水关键层的基本概念,通过建立隔水关键层力学模型,综合运用实验研究、理论分析、数值模拟等研究手段,系统分析了隔水关键层的基本力学特性及隔水性能,并将基于隔水关键层的保护原理成功运用到保水采煤的工程实践.提出基于隔水关键层的保水采煤原理.在岩层控制的结构关键层概念和传统的隔水层概念基础上提出了隔水关键层的基本概念,并阐述了其包含的3层含意.建立了隔水关键层的基本力学模型,并对其进行结构稳定性分析.建立了层状岩体渗流的非线性动力学模型,考察了隔水关键层渗流系统的平衡态特征,并给出了隔水关键层渗流系统的失稳判别条件.在传统物理模型试验的基础上,引入了数字图像相关法这一先进的分析手段,使试验布置更为简洁,同时可以进行位移场、应变场等全场力学特性分析,从而定量的再现了覆岩运动的全过程.从结构稳定性角度分析了隔水关键层的隔水性能,为实现保水采煤提供借鉴.采用数值模拟研究手段,基于岩石渗流-损伤耦合模型,模拟了隔水关键层的岩层移动及裂隙演化特征,同时系统分析了贯通裂隙与渗流分布的基本特征,并对渗流量进行了详细的统计和比较,总结隔水关键层的隔水性能.运用隔水关键层原理成功地在神东矿区开展了保水采煤实践,初步建立适合神东矿区的保水采煤模式.针对神东矿区某2个工作面的地质条件,建立数值分析及理论分析模型,通过数值模拟及理论计算,分析出覆岩中隔水关键层的基本特征.

According to the sustainable development viewpoint of ecology environment protection in themining area as well as the harmonious exploitation of resource and environment,the idea of water-pre-served mining emerged.In order to achieve the important subject of water-preserved mining,the basicconcept of water-resisting key strata was put forward,and the water-preserved mining principle based onit was explained.The mechanical model of water-resisting key strata was established and its basic me-chanical characteristics as well as wafter-resisting capability were analyzed systematically by the ways oftesting research,theoretic analysis,numerical simulation an engineering practice,and it protection prin-ciple was applied in the engineering practice of water-preserved mining successfully.The principle of water-preserved mining which bases on water-resisting key strata was put forward.The basic concept of water-resisting key strata was explained on the basis of structural key strata con-cept and traditional water-resisting strata concept.The water-preserved key strata are classified intothree types.The basic mechanical model of the water-resisting key strata was established and its structural sta-bility was analyzed.The nonlinear dynamical mechanical model of layered rock mass was established.The stability and instability condition of seepage system of water-resisting key strata were given.Based on the traditional physical model test,the advanced analysis means of digital image interrelat-ed method was introduced to make the testing disposal more concise.The whole field mechanical analy-sis such as displacement field,strain field were carried out,and the whole movement process of overbur-den strata was obtained.The water-resisting capability of water-resisting key strata was analyzed fromthe structural stability to provide reference for achieving water-preserved mining.According to the seepage-damage coupled model of rock,numerical simulation was adopted to simu-late the rock strata movement and cranny evolution characteristics of water-resisting key strata.Thebasic characteristics of the connected cranny and the seepage distribution were analyzed systematically.The seepage flow volume was calculated and compared in detail.The water-resisting capability of thewater-resisting key strata was summarized.The principle of the water-resisting key strata was applied successfully on the water-preserved min-ing of Shendong mining area,and the suitable water-preserved mining mode was established gradually.According to the geological conditions of some two workfaces of Shendong mining area,the model of nu-merical and theoretical analysis was established.The basic characteristics of the water-resisting key stra-ta in overburden rock were gained.