Study On Prevention And Control Of Water Before Mining At 1019 Working Face Of Wugou Coal Mine

Coal industry in China has a long history of development,is the pillar industry of China’s national economic development,China’s coal resources with large reserves,wide distribution,the characteristics of large variation of geological conditions.In recent years in the production of high pressure,large mining depth,multi aquifer under complicated geological conditions of coal mine,coal mine safety mining under threat and influence becomes even more prominent,the prevention and control of water and mine safety situation is more severe,so the prevention of water safety research of coal mine is very necessary.The five coal mine aquifer under the 1019 mining work as the engineering background,based on the field data acquisition,underground upward borehole drilling data,underground transient electromagnetic analysis of downhole geophysical prospecting,parallel electrical survey results,the 3D seismic exploration and large power frequency electromagnetic method exploration data,using field experimental observation and numerical simulation and theoretical analysis,mechanical test and theory research methods,aiming at the five ditch coal mine 1019 working face of the prevention and control of water safety mining,on the mechanical properties of rock,mining technology research,and the variation of wall rock disaster prevention technology and other aspects of the in-depth study.（1）The direct water-filled aquifer of 1019 working face is:the fourth aquifer（"four contained"）,10 coal top floor sandstone crevasse and 10 coal substratum aquifer.The"four contained"has less influence on the working surface,and the water of the coal seam in the top floor of 10 coal roof is less water-rich in most areas of the working area,and it has little effect on the water filling of coal seams.The complex of sandstone fissure aquifer and its hydrogeological conditions are important threats to working face mining.（2）The rock physical-mechanical test samples were tested in the top and bottom rocks of 10coal seam respectively,the physical properties and one-way unidirectional tensile,compressive strength,shear strength and mechanical properties test,etc.The load capacities of different rocks vary in size,and generally the sandstone is larger than the siltstone,and the siltstones are larger than the mudstones.The range of rock compressive strength varies widely,which is related to the composition,structure and the development degree of rock fracture.The roof has certain waterproof ability,which does not affect the safe mining of coal seam.（3）The results of water quality analysis of 12 working surfaces were developed,pour the water contains"contains four",reflect the"four containing"and 10 coal roof sandstone has certain hydraulic connection,but the"four containing"water supplies for sandstone mainly produce in the loose bed formation period,for a production phase,sandstone water water did not cause"contains four"concept of long hole of water level change,therefore,"contains four and ten coal roof sandstone has no obvious connection.（4）According to the test results of rock mechanics,an engineering geological analysis model is established.The numerical simulation of roof deformation and failure evolution law is carried out under the 1019 working face of aquifer under the FLAC^3D numerical simulation technology,accurately simulates the five ditch coal mining of 1019 working face,stress distribution and displacement of surrounding rock,each set of data simulation was simulated to study the mining along the longitudinal 10 meters,20 meters,30 meters,40 meters,50 meters,60 meters the change rule of surrounding rock.Through simulation study,1019 working face has the condition of safe mining.The relative parameters such as vertical displacement,vertical stress,horizontal displacement and horizontal stress along 10 m,20 meters,30 meters,40 meters,50 meters and 60meters along the mining face are obtained.（5）10 layers of strata covered in the roof of the working face of coal seam,the compressive strength of mudstone,fine sandstone,siltstone and medium coarse sandstone is different,the compressive strength of medium coarse sandstone is maximal,and the compressive strength of mudstone is the least,There is a big difference between lithology,with weak anti-deformation ability,It belongs to the soft and hard rock.The strength of mudstone and sandstone decreases with the distance from the roof of the coal seam,the actual roof is within 30 meters of the upper soft and hard cladding roof,Such roof is easy to construct actual control,it is not easy to produce a large amount of suspension in mining.（6）According to the"three down"mining rules,the maximum mining height 4.2m is calculated at the upper extraction section,and the sand protection safety coal pillar is 25.64m.According to the actual mining height working face 1021,the maximum height of caving mining thickness ratio of 4.69.The sand column height of sand control coal which needs to be reserved is1019 32.3m,which is less than the actual coal pillar 35.23m.Therefore,there is a small possibility of limestone water bursting in face mining.（7）With the method of water inrush coefficient method,P-M diagram method and theoretical calculation method,the water inrush coefficient of the bottom of the 1019 working face is0.041⁰.048Mpa/m,which is less than the water inrush coefficient 0.06Mpa/m stipulated by the regulation.Therefore,there is a small possibility of limestone water bursting in face mining.（8）Combined with the hydrogeological,mining conditions and the successful mining practices in the five Gorges coal mine,the prevention measures for the water damage in the 1019working face of the aquifer are worked out.