Study On The Mine Pressure Law And Support Adaptive In 31201 Fully Mechanized Caving Face Of Cun Cao-ta Coal 2 Mine

Cun Cao-ta 2 mine 31201 working face in a panel of 2#coal,coal seam thickness of 3.8～7.3 m,6.42 m,dip Angle of coal seam 1～6 °,nearly level category of coal seam,geological reserves of 6.3 million tons,recoverable reserves of 6.03 million tons,is expected in early September 2015 installation,extraction,recovery period of 13.5 months.With the continuous development of mining machinery equipment at present,the thick coal seam mining with large mining height are broken once all thick,but large mining height are broken in mining coal wall piece for serious,support problem such as poor stability,mine pressure appear sharp,not suitable for the working face the working face,and the hardness of coal seams is relatively low,as the unstable coal seam,unfavorable use slicing.After comprehensive consideration decided to adopt to the fully mechanized long-wall retreating type low caving mining method.Based on Cun Cao-ta coal mine 31201 face as the engineering background,through the theoretical analysis,physical model test,numerical simulation and data analysis to the underground pressure research methods,such as the migration of overburden stratum at the working plane,abutment pressure distribution and support adaptability problems in-depth system analysis,and puts forward specific solutions.The results of physical similarity model test show that the average periodic weighting step is 21.3 m,the periodic weighting has the phenomenon of "big and small periodic weighting"with alternating strength and weakness.The simulated mining-caving ratio is 1:0.83,and the average dynamic load coefficient of support resistance is 1.18 when weighting,which is smaller than that of general fully mechanized mining or high mining face.The vertical stress distribution is centered on the goaf,the stress releasing area is at the base of the basic roof and the model,and the stress increasing area is at the front and back of the coal wall.Periodic stress release occurs at the location of goaf with an average step distance of 20 m,which corresponds to periodic plastic failure of roof.The basic roof periodic weighting step of field observation ranges from 19 to 22 M.ZFY18000/25/39D shield hydraulic support produced by Zhengzhou Coal Mine Machine is selected as the working face support.The working resistance of the support is 18000 kN,which meets the support load requirement,and the support height is 2500-3900 mm,which meets the support height requirement.Inch Cun Cao-ta coal mine 31201 working face is nearly horizontal thick coal seam mining,the mine pressure law system research,to recognize the movement rules of full-mechanized caving mining strata,abutment pressure distribution rules of surrounding rock,and determine the support model and the selection and design of working resistance,to provide basis for the scientific and reasonable,make the economic and reasonable mining investment.For similar geological conditions of coal seam mining,providing theoretical reference.