论文部分内容阅读
石灰岩层往往成为煤矿开采防水害的主要对象,且淮南老矿区也发生了多次底板灰岩层突水,为解决新区水压高、传统隔水层薄的问题,提出改造或直接利用底板石灰岩层相对隔水性实现带压安全开采的构想,选择地处煤田中西部南缘的新集二矿为现场,综合运用岩石成分、水化学成分、岩石力学指标测试和微孔隙结构、渗透性实验等室内实验和水文地质钻探、物探、现场试验等手段进行研究。结果表明:1)四周为断层所切割,顶部为第四系和推覆体变质岩覆盖,500m埋深为界原地应力由浅部的张应力转变为压应力状态,深部岩层裂隙开启性差;2)水化学类型为Cl-Na型,矿化度大于1.5 g/L,岩层空隙处于沉淀充填状态;3)下组煤底板灰岩渗透性和富水性很差,可以看作相对隔水层,井下钻孔证实出水钻孔多靠近大型断裂,且出水量小而衰减快。首采面安全开采和第2个面的安全掘进证明下组煤底板灰岩为相对隔水层或稍加改造可以作为隔水关键层的结论是正确的。
Limestone layers are often the main targets of coal mining water hazards, and Huainan old mine has also occurred several times the limestone floor water inrush, in order to solve the new high water pressure, the traditional aquitard thin, the proposed transformation or direct use of floor limestone layer Relatively impermeable to achieve the concept of safe exploitation of pressure, the new coal mines located in the southern margin of the central and western parts of the coal field in the new site, the integrated use of rock composition, chemical composition of water, rock mechanics indicators and micro-pore structure, permeability test indoor Experimental and hydrogeological drilling, geophysical exploration, field tests and other means to carry out research. The results show as follows: 1) Four weeks are cut for the faults, the top is Quaternary and nappe metamorphic rocks cover, the local stress changes from shallow stress to compressive stress in the depth of 500m; ), The hydrochemistry type is Cl-Na type, the salinity is greater than 1.5 g / L, and the void of the rock formation is in the sedimentary filling state; 3) The limestone permeability and water- Downhole drilling confirmed that the water hole near the large fractures, and the small amount of water and fast decay. The safe mining of the first mining face and the safety excavation of the second face prove the correctness of the conclusion that the lower coalbed floor limestone is the relative aquitard or the slight alteration can be used as the critical aqueduct.