1、翻译部分英文原文Theoretical analysis and Numerical Simulation Study on failure depth of coal seams floor caused by mining under pressureShuancheng Gu Ang Li School of Architecture and Civil Engineering Xian University of Science and Technology Xian 710054,China Jianhuan Wang School of Chemistry and Chemical
2、 Engineering Southeast University Nanjing 210096,China Abstract: With mining depth increased, most coal mine will face high pressure groundwater threat. Bearing mining has already became a coal mining method universally employed in deep mine of China, one of key problems in coal mining above confine
3、d aquifer is how to determine the depth of destroyed floor due to mining influence ,but the conventional method of mining failure depth from coal seam floor in coal mining above confined aquifer possesses high cost and study cycle long and other shortcomings. In the paper ,taking mining No.5 Coal Se
4、am of Cheng-He Mining Area as an example ,this paper analyzes a method which combines the numerical simulation with theoretical calculation is brought forward, while the testing data are compared with those from the in situ measurement, drawing detailed reliable actual information can ensure safety
5、in mining, it can be dynamically reproduced that the development and failure process of the whole floor strata during mining advance .The numerical simulation results educes the 1213m failure depth of the coal seam floor of mining working face, meanwhile, the results may be used to guide practice wi
6、th similar water prevention work of a working face of bearing mining and design of the water control method, and also provide scientific basis. Key words: coal seam floor； failure depth of coal floor； theoretical analysis； numerical simulation I. INTRODUCTION Chinas coal reserves are very abundant,
7、coal is also a very wide range, but several hundred million tons of coal reserves of coal mine water at the bottom of the Ordovician limestone aquifer confined there, so mine in the mining process, often be subjected to threat by the Ordovician confined water inrush. Mining coal in the mine floor an
8、d the floor with pressurized water pressure under the influence of the interaction, will form a seam from top to bottom floor rock formation mining water flowing fractured zone, The effective impermeable layer protection zone and conduction band of water pressure rise zone. The impermeable layer of
9、seam floor resistivity water capacity depends on the effective resistivity water capacity of impermeable protective layer, impermeable layer of protection is only effective in order to effectively ward off the threat of confined water. Coal seam floor mining failure is due to the impact of mining di
10、sturbance, the original ground stress equilibrium is broken, re-distribution of ground stress .in the ground stress to reach a new equilibrium, there must be the release of strain energy, so that mining water flowing fractured rock zone Structure change. Therefore, the resistivity water capacity of
11、mining water flowing fractured rock zone is weak, can be regarded as non-water-blocking capacity of rock. Confined water from the mining point of view of safety, the correct evaluation of mining water flowing fractured zone of the actual thickness, that is, the floor-broken depth to accurately deter
12、mine the bottom impermeable layer of water blocking the effective protection capabilities. Shows the floor-broken depth prediction and control of water inrush is important in decision-making. The present study mining bearing mining coal seam floor-broken depth, mainly by comprehensive observation si
13、te (drilling injection pressure water test method, ground penetrating radar and ultrasonic detection method)1-2, similar elastic material model simulation and photo elastic experiment techniques mine the floor-broken depth. These methods are either the high cost or long cycle； either too simplistic
14、test conditions, it is difficult in the bearing mining floor-broken depth application .To compensate for this deficiency, in this paper Cheng-He Mining Area No.5 seam mining face engineering background, application of rock failure process flow-stress coupling analysis system (RFPA2D-flow)3-6, from t
15、he perspective of fluid-solid coupling simulations analysis in high-confined water in mining, the coal seam floor strata failure process and floor-broken depth, to explore the basic law of coal seam floor-broken depth development. II. MINING FACE HYDROGEOLOGY CONDITIONS Cheng-He mining area No.5 sea
16、m mining under pressure face is located northern four mining area of mine field, north and south sides are solid areas, within No.5 seam, buried depth of 270340m, the average buried depth of 300m, No.5 seam average thickness of 4.2m. Mechanized mining using long-wall mining machine, all falling for management across the roof. No.5 seam elevation of the face below the static water level Ordovician +375m, the confined mining areas, the main factor
