榆树湾煤矿河流下安全开采数值分析

Numerical Simulation of Safety Mining Under a River in Yushuwan Coal Mine

在分析榆树湾煤矿首采长壁工作面的水文及工程地质的基础上，运用RFPA^2D对其首采面开采分别进行走向和倾向两个数值模拟试验．试验表明，覆岩最大裂隙带的高度为92m．通过模拟表明在距工作面40-60m处的地表土层出现了不同长度的裂缝，地表裂缝未和裂隙带贯通，裂隙带与地表土层裂隙之间，在倾向模拟时和走向模拟时分别有30，18m的土层隔离带．通过进行安全分析得到了最小安全防水煤岩柱的尺寸为95m，表明数值模拟结果与工程开采实践基本一致．进一步为河流下安全开采提供了可行性．

Hydrology geological conditions as well as engineering geological conditions for the long walll working of Yushuwan coal mine were analyzed and the first mining face was numerically simulated along both strike and dip directions by using the software RFPA^2D. According to the experimental data, the maximal height of fracture zone is 92 m. The simulation shows that fractures with different lengths can be seen in surface soil layer 40 - 60 m far from the working face and these surface fractures have not been connected with the fracture zone. Between fracture zone and surface fractures, there is an isolation layer of 30 m thick according to the dip simulation and 18 m according to strike simulation, respectively. The minimum height of coal and rock pillar for preventing water from gushing is 95 m based on practice, indicating that the result of numerical simulation in good accordance with the practical. So the coal caving under the river was safe and feasible.