【作者】 张伟杰；

【导师】 魏久传； 郭建斌；

【作者基本信息】 山东科技大学 ， 地质工程， 2010， 硕士

【摘要】 本文针对保德煤矿13#煤奥陶纪灰岩(奥灰)承压含水层上安全开采,分析了研究区所在天桥泉域岩溶水补、径、排条件,总体水化学特征及强径流带特征；在此基础上,结合研究区水位资料、钻探资料及抽水试验资料,以水化学分析和GMS数值模拟为手段,详细研究了井田奥灰含水层富水特征、岩溶水径流条件变化规律、水位动态及渗流场特征。建立了底板裂隙岩体断裂破坏的压剪模型,结合库伦-摩尔破裂准则和有效应力原理,对底板裂隙岩体在渗流-应力耦合作用下的断裂损伤机制进行了探讨,并经理论推导,获得了单裂隙岩体断裂强度计算公式及多裂隙岩体断裂强度计算公式,为底板导水破坏带深度及承压水导升带高度计算奠定了理论基础。分析了底板突水的影响因素；在下三带理论指导下,基于底板多裂隙岩体断裂强度公式及I型应力强度因子公式,推导出渗流-应力耦合作用下底板导水破坏带深度及承压水导升带高度的计算公式；从底板隔水层厚度和岩性组合形式两方面着手,结合研究区沉积特征,对底板隔水层阻水性能作了综合评价；基于岩体极限平衡理论,综合考虑工作面斜长、隔水层厚度及岩性组合,推导出隔水层突水极限水压值计算公式；阐述了裂隙型底板突水动态机理,认为裂隙型底板突水是渗流-应力耦合作用不断强化的过程,矿山压力向底板深部传播,使底板岩体内应力状态不断变化,渗透压力也随之变化,促使底板隔水层上部和下部裂隙的扩展和贯通,最终整个隔水层贯通,造成突水。运用突水系数法和工作面斜长L=200m时底板突水极限水压值分别对保德煤矿13#煤底板突水危险性进行了预测,划分了突水危险性分区。通过两种方法对比分析,当L=50-70m时,底板隔水层突水极限水压值与隔水层厚度拟合线(Pz-M)和突水系数Ts=0.1MPa/m时工作面安全水头压力与隔水层厚度关系线(Ps(0.1)-M)符合程度较好；当L=100-150m时,Pz-M和Ps(0.06)-M符合程度较好；而当L进一步增大时,Pz-M逐渐偏离Ps(0.06)-M,且随L不断增大,隔水层厚度对底板突水的影响因子逐渐减小。更多还原

【Abstract】 The safety mining of the 13th coal seam in Baode coal mine on the Ordovician limestone confined aquifer was researched in this paper. The recharge, run off and discharge conditions of Tianqiao spring basin in our studying area, general hydrochemical characteristics and intensive runoff zones characteristics were firstly analyzed. The water yield property, karst water runoff condition evolution, water level variations and seepage field characteristics of Ordovician limestone in our studying area were detailed researched. The adopted methods were hydrochemical analysis and GSM numerical simulation combining with area water level data, drilling data and water pumping data. The fracture destruction compression-shear model of fractured floor rockmass was established. And the fractured floor rockmass’ rupture and damage mechanism under seepage and stress coupling was discussed on the basis of Mohr-Coulomb fracturing criterion and effective stress principle. The fracture strength computing formulas of rockmass with a single fracture and fractured rockmass were obtained after the theoretical derivation. That layed theoretical foundations for the calculation of floor failure depth and damage zone height. The affecting factors of floor water-inrush were analyzed. The computing formulas of floor failure depth and damage zone height arised when theory solutions for fracture strength of fractured floor and the mode I stress intensity factor were referenced based on the "down three zone" theory. From the perspective of water-resisting layer’thickness and lithological association, the separating water ability of water-resisting layer was evaluated comprehensively and the sedimentary characteristics were researched. The computing formulas of water-resisting layer’ultimate water-inrush pressure were derived with the comprehensive consideration of working face width, water-resisting layer’thickness and lithological association on the basis of rock mass limiting equilibrium theory. The fractured floor water-inrush dynamic mechanism was presented, and it was thought that the water inrush from fractured floor was by the strengthening of seepage and stress coupling. The underground pressure propagation to the floor led to the ever-changing of stress state in the floor rock mass, and also the seepage pressure,which promoted cracks’ extension and coalescence, even the whole water-resisting layer, the water inrush happened at last. The water inrush coefficient method and ultimate water-inrush pressure of water-resisting layer with L=200m were applied to predict the water inrush danger of 13# coal seam in Baode coal mine and divided the water inrush danger areas respectively. With the comparison it was found that Pz-M and Ps(0.1)-M matched well when L=50-70m.And Pz-M was the fit line of ultimate water-inrush pressure and thickness of water-resisting layer, Ps(o.i)-M was the relation line of security pressure and water-resisting layer thickness when Ts=0.1MPa/m. Pz-M and Ps(0.06)-M matched well when L=100-150m. While L increased a bit, Pz-M deviated from Ps-M gradually, and the increase of L decreased the effect of water-resisting layer’s thickness on floor water inrush.更多还原