Research Of Influence Scope In Goaf Collapse Of Coal Mine

Since the reform and opening up until the beginning of twenty–first Century, it is very common that too much emphasis on economic benefits while ignoring the vile impact on the environment, which leads to too much coal mining accidents. A coal mine in Hunan since building mine, has been used in management with full collapse method. Because they leave the mined out area behand with no treatment, it is seriously affected the normal life of local residents, such as the goaf overburden area surface subsidence, fissures in building, pavement cracking, pond and well dried up. Combined with this project example, This article using analytical method, probability integration method and finite element numerical analysis method to research the influence scope in goaf collapse of coal mine. Then, a proper scheme is given here.(1) On the basic of the early site investigation in the study area, we got the basic situation of the mine: using inclined shaft in mining development system and wall mining method along strike, with a full management of roof fall method and simple type of hydrogeological conditions, and its engineering geological properties of the surface soil is poor, the other rock belongs mid-hard to hard rock. The mine is divided into –20m, –55m, –90 m, –150m, –200m, –250m and –300m seven level. After statistics of the goaf situation, goaf distribution positions is in –150m ~ –300m level, the total area of the goaf is 181,892.43 square meters, the total volume is 685,760.28 cubic meters. Those statistics has shown that the mining subsidence damage mainly three types: surface buildings damage, roads damage and partial surface ground collapse. Finally, we draw a map of plane projection goaf and got the test-based surface goaf collapse scope map.(2) Based on the movement basin characteristics, this paper choose mine movement angle to determine the risk of moving boundary of the movement basin. With totally 25 border points, moving towards the use of angle δ = 70 °, moving down the angle β = δ–0.6α, moving uphill angle γ = 70 °movement topsoil angle φ = 45 ° is substituted into the formula, and finally it got the 25 points of ground subsidence radius of influence between 153.80 ~ 379.57 meters, then put 25-point connections into a closed circle, that is analytical method delineated the scope of the goaf collapse.(3) According to the 2006 collapse of the scope of the results to invert the desired parameters probability integration method to obtain 4, 6, 7 seam tgβ 1.58, 1.76 and 1.67, respectively, selected 23 border points substitution to give the ground subsidence radius of influence between 169.30- 253.95 meters, the 23–point connections into a closed circle can be delineated into a closed surface subsidence affected areas.(4) Using finite element analysis software to create a threedimensional solid model with 1400 m × 1300 m × 500 m, select the mole Coulomb criterion points –150 ~ –200m, –150 ~ –250m and –150 ~ –300m mining simulated three levels in –250 ~ –300m level has been the scope of surface subsidence area.(5) With an integrated three methods, the final choice is numerical simulation methods for this article of influence scope in goaf collapse.