Study On The Reliability Of Disc Cutter Breaking Rock By Physical Model Test On The Jointed Rock Mass

With the development of underground space,the application of TBM has become more and more extensive.The reliability of disc cutter is affected significantly by the joints and sandwich in the rock mass during the process of disc cutter rotating.The force,cutting depth and wear of disc cutter would be effected significantly by the change of joint orientation and spacing.Due the presence of weak sandwichs,the disc cutter often experiences abnormal wear and cutter head would be stuck in mixed ground,which can affect the construction cost and progress of the project directly.With the purpose to study the influence of joint characteristic parameters and mixed ground on rock breaking mechanism and disc cutter wear,experimental explorations that contain miniature cutter head with double cutters are conducted in this paper to get the data of cutting force and penetration.By using numerical simulation methods,the reliability of the experimental results is verified.The main work in this paper includes the following four aspects:Firstly,based on the Rolling Indentation Abrasion Test(RIAT)model,a scaler disc cutter rotating rock breaking experimental device would be made.The complete rock samples,jointed rock samples and weak intercalated rock samples would also be prefabricated.The use of MTS hydraulic servo press is used to complete the hierarchical loading of rock samples under different formation parameters.In the meanwhile,the thrust,rolling force,penetration,and wear data of the disc cutter would be obtained.Secondly,the experimental data could be categorized.According to the variation of the cutting force and penetration with the change of the joint orientation and spacing,the optimal rock breaking angle of disc cutter would be inferred.The data of cutting force and penetration can be brought into the empirical formula,and the change laws of the specific energy and the wear value can be obtained,which would be compared with the experimental data.Therefore,the empirical formula can be revised.Thirdly,through wavelet packet decomposition and logistic regression theory,the vibration signals which obtained by test would be processed to obtain the reliability index for different conditions of the normal thrust,joint orientation,joint spacing and mix ground.According to the reliability result,the failure threshold of disc cutter would be inferred to predict the cutter life.At last,the finite element program ANSYS/LS-DYNA can be used to numerically simulate the three-dimensional rotary cutter rock breaking process.The data of disc cutter cutting force during the rock breaking process would be extracted and classified,and the variation law of the cutting force under different formation conditions can be obtained.The cutting force of disc cutter which obtained by the numerical simulation could be brought into the empirical formula to calculate the specific energy and the wear value under different geological conditions.