| In recent years,with the rise of intelligent mine construction in China,the popularization and application of full section boring machine（TBM）in deep coal mine rock tunneling has been developing rapidly.However,the supporting anchor net spraying support has become a technical bottleneck that restricts the efficiency of TBM tunneling under the above conditions and affects the construction safety due to many process conversions,the construction schedule of support often lags behind the speed of TBM tunneling,and the failure to meet the requirements of support strength of complex rock sections,which need to be studied and solved.Therefore,the research on the deformation and mechanical characteristics of new assembled steel plate support structure for coal mine tunneling by TBM has certain theoretical significance and application value to solve the technical problems of deep coal mine tunneling by TBM.The paper takes the TBM tunneling in a mine in Huainan with a high extraction lane as the engineering background,and uses a combination of laboratory footprint structural model strength test and numerical analysis to carry out the research on the force deformation characteristics,destabilization damage characteristics and bearing capacity of this new type of support structure under uniform and non-uniform loads.The main research contents and results are as follows.1.The strength test study of the new assembled steel plate support structure of TBM tunneling coal mine roadway under uniform load was carried out.Based on the analysis of the test results,it is shown that the support structure is characterized by the weak surface of the tube sheet first and then the overall instability;except for the local buckling of individual steel tube sheets,each steel tube sheet is mainly compressed in the circumferential direction,and the maximum compressive strain value reaches about5500με,the maximum radial deformation occurs in the middle of each tube sheet,and the maximum radial deformation is 37.52mm at the time of damage;the yield load of the steel plate support structure is 2703.4k N,and the ultimate The yield load of the steel plate support structure is 2703.4k N,and the ultimate load capacity is 3972.2k N.2.The strength test of the new assembled steel plate support structure of TBM tunneling coal mine under non-uniform load（λ=1.5）was carried out.The analysis shows that under non-uniform load,the overall radial displacement of the steel plate support structure is characterized by the large load tube piece to the inner ring and the small load tube piece to the outer ring,and the maximum radial deformation is 86.42mm at the time of damage;the yield load of the support structure is 2720.496k N and the ultimate bearing capacity is 2763.2k N;compared with the uniform load test,the yield load of the structure under non-uniform load is reduced by 29.1%and the ultimate bearing capacity is2763.2k N.Compared with the uniform load test,the yield load of the structure under non-uniform load was reduced by 29.1%,the ultimate bearing capacity was reduced by 30.4%,and the maximum deformation at damage was increased by 130.3%.3.Numerical analysis of the steel plate support structure was carried out.The structural model of steel plate was established by ABAQUS,and the numerical analysis under uniform and non-uniform（λ=1.5）loading was carried out and verified by the results of the full-scale test.The results show that under uniform loading conditions,the axial force at the joints of the support structure is larger,and the bending moment at the joints and the span of the pipe sheet is larger than other parts;under non-uniform loading（λ=1.5）conditions,the axial force of the support structure is slightly reduced,and the bending moment values are both positive and negative,and the bending moment is higher than uniform loading;the ultimate bearing capacity of the structure is exponentially negatively correlated with the lateral pressure coefficientλ(Fu=7770e-0.6λ).Figure[76]Table[6]Reference[76]... |
PDF Full Text Request