Research On Optimization Technology Of Supporting Half Coal Rock Roadway In No.2 Coal Seam And No.3 Mining Area Of Zhaojiagou Mine

This paper mainly focuses on the optimum design of supporting scheme of the mining roadway in No.2 coal seam of Zhaojiagou Mine.On the premise of fully understanding the original supporting design of No.2 coal seam and a series of difficulties in controlling the surrounding rock of roadway in the production process,the paper uses theoretical calculation,numerical simulation and field industrial test to draw the following conclusions:0.8m x 0.8m bolt-to-bolt interval is adopted.The roof and two sides of the roadway in the third mining area of No.2 coal seam can be obviously controlled by row spacing,and superior support effect has been achieved in the field industrial test.The main research results are listed as follows:(1)Based on the geological structure,hydrogeological conditions,roof and floor lithology and interlayer relationship of No.2 coal seam,the industrial evaluation of roof and floor conditions in No.2 coal seam No.3 mining area is made.According to the coal seam occurrence and stress occurrence status,and combined with the production capacity and actual production requirements of the underground working face,the cross-section shape and size of the quasi-mining roadway in No.2 coal seam No.3 mining area are determined.?(2)Based on the theory of bolt suspension support,the optimum design of support parameters of the mining roadway in No.2 coal seam of Zhaojiagou Coal Mine is carried out,and the optimized and improved support scheme is put forward.It is emphasized that under the condition of broken roof,the full-length anchored pre-stressed bolt is preferentially used,and the supporting components such as wear-reducing washer and centering ball cushion are used together to improve the applied strength of pre-stress and its diffusion range.Surface of surrounding rock can form a compression zone with a certain thickness to enhance the stability of surrounding rock.(3)Using numerical simulation software FLAC~3DD 5.0,based on the mechanical parameters of the surrounding rock of No.2 coal seam,an equivalent simulation model is established.By simulating the support effect of 0.8m x 0.8m anchor row spacing under the condition of different section sizes along the conveyance channel,it is found that 0.8m x 0.8m anchor row spacing can be effectively controlled in No.2coal seam of Zhaojiagou Coal Mine,and the roadway deformation and roof separation and horizontal fault can be reduced.Dynamic,enhance the stability of roadway surrounding rock.(4)Combined with the loose zone test of surrounding rock in the mining face of No.2 coal seam No.3 mining area,which was carried out in the field industrial test,the characteristics of high surrounding rock strength in the side wall of No.2 coal seam working face and easy influence of large mining and disturbance were obtained.And through the on-site monitoring data records of the mine pressure of the quasi-mining roadway in the third mining area of No.2 coal seam,targeted optimization of the roadway support scheme.Through numerical simulation and on-site measurement and verification analysis,it is concluded that the support scheme of the quasi-mining roadway in the third mining area of No.2 coal seam in Zhaojiagou Mine is reasonable in design and remarkable in support effect,can realize the deformation control of the roof and two sides of the roadway,and effectively meet the requirements of underground safety production.