Study On The Technology Of Coal Seam Mining With Filling Water Threatened Under The Village

Laiwu Nanxiaye Coal Mine Co. Ltd. is located in Yanzhuang Town, GangchengDistrict, Laiwu City. It grew out of the original Nanxiay coal mine which wasintegrated with its neighbouring original Daishan coal mine by oversizing, and was putinto use in2010after technical reformation. As a result of mining in recent years,remaining reserves of3and4coal seams become less, it will be transferred to the19coal mining. Mining with filling method will be adopted by19coal seam. Therefore,the design of the mining with filling method is needed. Coalfield is in the horizontalrange with many buildings on the ground. Villages, enterprises and institutions are in adense distribution. The majority of recoverable reserves are under the buildings. In fact,it is a mining project under buildings. Hence, the surface deformation of the19coalseam is necessary to be calculated in advance.. In addition,19coal seam is threatenedby the Taiyuan formation four, five and six ash and Ordovician limestone water.Therefore, the failure depth of the roof and floor of the19coal seam needs to beestimated. Based on the above problems, the main research work of this paper includesthe following aspects:(1) according to the mining with filling design schemes of the supply situation ofthe site materials and requirements of the strength design of the filling body, tests aremade for the use of filling aggregate and cementitious materials. Chaning rule of thestrength of the filling body with material ratio has been found. Together with the rulesof the strength of the filling body varies with the variation of concentration under thecertain material ratio. Filling ratio which can meet the practical engineering needs hasbeen found.(2) the principle of probability integral method for the prediction of surfacedeformation is elaborated briefly. According to the actual conditions of Nanxiaye coalmine19coal seam, as well as considering the mining experiences of3coal seam and4seam, parameters are optimized. The surface deformation after19coal seam mining isestimated using the probability integral method combining with the computer aidedcalculation.(3) principle of FLAC3Dprogram calculation is introduced and the advantages ofthe program in the geotechnical engineering problems during calculation are stated.Model is established on the basis of19coal seam conditions and the actual geological conditions, the deformation of ground surface coal mining area is analyzed through theuse of FLAC3Dnumerical analysis, deformation law of19after trial excavation andfilling is obtained. In the calculation process, the main section and the displacementchange tendency towards the main profile on the main points are recorded, and thecorresponding function is fitted by using MATLAB, the maximum horizontaldeformation of the surface, the maximum tilt deformation and maximum curvaturedeformation are calculated by using the function of deformation. The results of twodifferent methods are analyzed and compared.(4) on the basis of the obtained prediction surface deformation value, the failuredepth of the roof and floor of19coal seam is estimated in further using the reliablemodel and parameters, and compared with the hydro geological data19coal seam.Based on the two main aspects, that is the expected surface deformation and roof andfloor failure depth, demonstrates the feasibility of the application of the mining withfilling method for19coal seam of Nanxiaye coal mine is demonstrated.