Jianzhuang Mining 4^-2302 Working Face Support Pressure And Study On The Law Of Mineral Pressure Manifestation

This thesis takes the 4^-2302 working face of Jianzhuang Mining as the object of study,and derives the mine pressure manifestation pattern of the working face and the two chutes through theoretical analysis,numerical simulation and industrial testing.The results achieved in the thesis are as follows:（1）Based on the key layer theory,the key layers in the overburden layer on the working face were calculated,and a theoretical model of old top breakage was constructed,resulting in an initial breakage distance of 58.4～63.3m and a periodic breakage distance of 23.8～25.9m on the working face.（2）Analyse the support pressure distribution of the working face under the influence of mining,and study the characteristics of the support pressure distribution along the strike and inclination of the working face respectively.Among them,the mechanical analysis of the coal pillar in the section obtained that the coal pillar was affected by the superposition of lateral pressure on both sides.（3）According to the theory of slip line field,the process of bottom drum appearing in 4^-2302 working face is explained,and the maximum damage depth of bottom plate is calculated as 5.7 m.According to the semi-infinite theory of elastic mechanics,the stress distribution characteristics of bottom plate are calculated,and it is analysed that the bottom drum appears mainly due to vertical stress,and the vertical stress reaches15 MPa at the depth of 4 m in the bottom plate of the roadway,and the bottom drum appears from the middle at the very beginning.The bottom drum was analysed to start from the middle.（4）The numerical simulation software FLAC^3D was used to simulate the mineral pressure manifestation during the recovery process of 4^-2302 working face,and it was pointed out that the influence of the overhead support pressure of the working face,the overhead distance of 0～30m is the intense influence area,the overhead working face distance of 30～70m is the strong influence area,and the overhead working face range of 70～120m is the general influence area.（5）Three kinds of measures were designed to control the bottom drum of the zoning section,and the analysis of mine pressure observation was carried out systematically to obtain the initial incoming pressure of 40～52m and the periodic incoming pressure of 25.4～27.1m at the working face,which verified the overburden breaking law in the key layer theory.The analysis of the conventional mine pressure observation in the two chutes pointed out that the deformation of the roadway surrounding rock within 45m of the overburden workings was gradually increasing under the influence of mining,and attention should be paid to the protection of the workings against scouring.The thesis has 52 figures,8 tables and 87 references.