| In recent years,with the continuous acceleration of intelligent mine construction in China’s coal industry,the application of full-section rock boring machine(TBM)technology in underground mining roadway excavation is emerging.In particular,following the successful use of full-section TBMs to bore the long main inclined shaft in Shendong Fulianta Coal Mine,the use of this technology to construct the long(main and secondary)inclined shafts of the Cretaceous-Jurassic strata in the western region has become an important development direction for new well construction in the future.However,the construction of the long inclined shaft of the water-bearing chalkJurassic strata is still in the initial application stage due to this technology,and in addition to the continuous iterative improvement of the full-section TBM equipment,the corresponding roadway support technology cannot meet the engineering needs and needs to be studied and solved urgently.Therefore,this paper takes the long main inclined shaft of the Cretaceous-Jurassic strata of TBM construction in a certain mine in Yulin,Shaanxi Province as the engineering background,and adopts the research method of indoor test,theoretical analysis,numerical analysis and field measurement,focusing on the excavation support and surrounding rock stability of TBM construction across the aquiferous formation of the Cretaceous Luohe Formation.The main studies completed are as follows:(1)The mineral composition,porosity,(single)triaxial mechanical properties and other tests were carried out on the rock samples of the Cretaceous Luohe Formation of a mine in Yulin,Shaanxi.The results show that the mineral composition of these rocks is mostly quartz and feldspar,and is weakly cemented by mud,iron and calcium.The porosity of the rock is about 5.03%,and the pore size is between 1 and 10 um,accounting for 69.1%;The compressive strength of the rock is about 0.432 Mp,the adhesion force is 0.38 MPa,and the internal friction angle is 21.37°.(2)Taking the section buried at the depth of 205 m in the TBM construction of the mine as the simulation object,ANSYS software was used to carry out numerical analysis of the two primary support schemes of roadway bolt + anchor cable,long and short bolt support,and the analysis showed that the anchor + anchor cable support roadway surrounding rock roof converged to 10.5mm,the surrounding rock convergence on both sides of the surrounding rock was 4.97 mm,and the anchor cable,The maximum axial force of the bolt is 44.2KN and 38.6KN,the convergence of the surrounding rock roof of the long and short bolt support roadway is 11.71 mm,the convergence of both sides of the surrounding rock is 5.89 mm,the maximum axial force of the 3.5m long bolt is 31.08 KN,and the maximum axial force of the 2.8m short bolt is 45.72 KN.(3)ANSYS software was used to analyze the anchor + anchor cable + net spray,long and short bolt + net spray support schemes.the analysis shows that the convergence of the surrounding rock roof of the bolt + anchor cable + net spray support roadway is 8.67 mm,the convergence of both sides of the surrounding rock is3.61 mm,the maximum axial force of the anchor cable and the bolt is 45.54 kn and18.89 kn,respectively,the convergence of the roof of the surrounding rock of the long and short bolt + net spray support roadway is 10.93 mm,the convergence of both sides of the surrounding rock is 5.31 mm,the maximum axial force of the 3.5m long bolt is27.54 kn,and the maximum axial force of the 2.8m short bolt is 18.39 kn.Based on the above analysis results,combined with the characteristics of TBM construction long main inclined shaft construction method,bolt + anchor cable + net spray support was selected as the main inclined shaft support scheme for TBM construction of the mine.(4)The on-site monitoring of the inclined shaft roadway in the T BM construction section of the mine was carried out,and the deformation of the surrounding rock of the section roadway after the T BM excavation,the displacement of the roof plate and the force characteristics of the anchor cable after the construction of the roadway were obtained.The measured results show that the axial force of the anchor cable at the top of the spandrel and arch is between 34.4~65.3KN.The surrounding rock at the top of the roadway has the largest deformation(25mm),and the surrounding rock on both sides has less deformation.The numerical simulation is basically consistent with the actual field measurement results.The measured results show that the optimized use of bolt + anchor cable + net spray support form can effectively control the deformation of the surrounding rock and ensure the stability of the inclined roadway.Figure [60] Table [16] Reference [77]... |
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