| The basic rule of overlying strata’s movement and development on the working face with large mining height are introduced in the paper firstly, meanwhile, the basic principle of bearing stress distribution on fully mechanized working face are expounded, the distribution relationship between the two is determined and the mining key stratum in the overburden strata and its effect on the bearing stress distribution is analyzed. Based on the research of surrounding rock of roadway of fully mechanizedworking face with large mining height in YiDe coal mine, the paper analyzed the influence factors of bearing stress in advance on the two lane. According to the field observation data of surrounding rock, the phenomenon is found that the relationship between forepole pressure frequency and size and the mining rate existed positive correlation. When the pressure was coming, the stress concentration phenomenon was most serious in the angle of roof and floor of roadway, the floor and roof was second and the two sides of roadway was the weakest. The pressure’s coming of advance support stress and the deformation process of surrounding rock were discussed. By using the limit equilibrium theory, the scope and size of abutment stress distribution was calculated in uniform mining process. By adopting the combination of numerical simulation and field industrial test method, the The modified characteristics of the two roadway’s surrounding rock of YiDe coal mine was studied. The distribution law and its characteristics of deep surrounding rock support stress was analyzed and the mechanism of advance support stress’s influence on deformation of roadway was explained. The main conclusions include:(1) Analysis shows that the model and the Mohr-Coulomb elastic-plastic strainsoftening model of the essential differences between the two contact constitutive model,the results show that the strain softening Mohr-Coulomb model is more fitting toanalyze the actual situation reflects the surrounding rock good strain softening.(2) Constitutive model and parameter setting, and numerical simulation XX, YY,ZZ direction roadway stress distribution, XY, XZ, YZ direction roadway stressdistribution, distribution of shear strain increment, the stress state of surrounding rockunit body distribution and bolt maximum axial force and so the results were analyzed,in order to maintain a stable roadway provides a theoretical reference.(3) According to the data obtained by observing the roadway bearing stresses, stope support ahead of stress about50m in front at the start of the stope continues toincrease. With the face after forward, supporting increased stress amplitude trough alsobegan corresponding increase. When pushed into position before working for the coalwall10m away at the support stress reaches the maximum2.5Mpa. Then they began togradually decrease, approaching the original rock stress.(4) Surface analysis of roadway surrounding rock convergence of data, determineto move forward with the mining face, both help and roof and floor mount with Faceroadway in a corresponding increase in the average amount closer to the roadwaybetween two slightly greater than the amount closer to the top floor. Therefore, todetermine the length of the stope advance support of not less than50m, an increase ofhydraulic prop plus1.2m hinged beam, I-beam girder bottom end of the drill to preventsingle column, each hinged back two semicircular wooden beams, set up to fight shed,step away from the500mm, vertical distribution.(5) Large fully mechanized mining face in stress ahead of supporting a range ofabout60~80m, in which the range of0~15m roadway affected by the intensepressure in the face of job stress position supporting approximately2.5~7m peaked.Mining within the scope of work in front of0-80m, roof and floor as the largest miningwhen the average speed is closer to everyday9.6mm, up to a maximum amount closerto average19.5mm, supporting peak stress point when the stress concentration factor is2.8. |
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