| Because of the low strength of surrounding rock,the large deformation of roadway,the poor stability and the difficulty of support,it is very important to determine the supporting parameters and to study its stability.The research on the natural science foundation of Shanxi province "thick coal seam roadway with high solid structure characteristics and stability of prestressed anchor and control of Taiyuan University of Technology and Shanxi County Golden coal project" the coal roadway Xingxian optimization research "and based on the method,numerical simulation and engineering test analysis by combining theoretical analysis,study on the stability,the supporting structure of roadway in thick coal seam.The main conclusions are as follows:(1)thick coal seam roof rock roadway of low strength,crack development,there are a lot of broken zone in the shallow roof and coal rock boundaries,unstable coal thickness is more than 8m,suspension point unknown or does not exist,the key to control this kind of roadway is to give full play to the layout and the bearing capacity of anchor prestressed high.Thick seam arch coupling support structure formation,combined beam structure can promote the formation of deep arch deformation in the effective control of the shallow,and effectively improve the bearing capacity of arch,the arch of the deep shallow beams have the effect of reducing span and decompression.The two are coordinated with each other and adapt to each other to form a perfect prestressed concrete bolt rope coupling support system for the extra thick coal seam roadway,so as to improve the stability of the roadway.(2)The analysis of the factors influencing the supporting structure of roadway in extra thick coal seam shows that the key influence parameter is pretension and length of anchor rope.Pretightening force of hours can not form stable bearing structure in the roof above is too large,easy to cause the anchor failure or damage caused by structural instability,the pretightening force of bolt is reasonable value for 60 KN,150KN cable,cable preload can be applied reasonably to improve the bearing capacity of Bolt Beam 113.74%.A reasonable increase in anchor length is helpful to increase the bearing structure,but the bolt and cable length is too large will not increase or even decline in the rock bearing,is not conducive to play active role in supporting the bolt and cable anchor,reasonable length is 2.4m,the length of the anchor was 8m.(3)through the study on the stability of the supporting structure of roadway in thick coal seam that the supporting parameters after the optimization of composite beam,bearing scope of arch was increased 17.71% and 10.27%,bearing increased 64.36% and 46.86% respectively,the optimization scheme can give full play to the active role of anchor cable,bearing,bearing a significantly improved support structure.Through the thick coal seam and arch coupled supporting of roadway surrounding rock stability analysis shows that the optimization scheme of the surrounding rock in the horizontal and vertical stress concentration has improved significantly,up and down the two lane high angle shear stress concentration were decreased by 10% and 15%;roadway roof and floor closer to the amount of two,the relative amount of help convergence were reduced 42.1% and 45.2%,the plastic zone of the surrounding rock is greatly reduced;anchor support structure enhance the carrying capacity of the more obvious,to enhance the rate of 17.5%-47.7%.(4)of the 13205 roadway bolt(cable)shows the working load and displacement monitoring: support in the process of anchor cable increases by 31.3%,increased by 12.6%,the maximum roof separation 48.5mm,the convergence between the two sidewalls and the lower roof maximum amount were 48 mm and 61 mm,which indicates that the thick coal seam roadway with high prestressed anchor-cable coupling support structure of tunnel stability,effectively control the deformation of surrounding rock. |
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