Research On TBM Rock-Mechanical Interaction Meehanism And Control Optimization Method Based On Classification Constrain

With the development of the 14th Five-Year Plan,overall promotion of infrastructure construction has become the main development direction.Complete system,efficient and practical,intelligent,green,safe and reliable have become the basic requirements of modern infrastructure construction.In order to lay out the general direction of new infrastructure construction,full face tunnel boring machines are more and more widely used,it appears in many large-scale infrastructure construction projects in the 14th Five-Year Plan.According to statistics,TBM is the first choice for most of the tunnels under construction or to be built.With the rapid development of economy,mechanized,automatic and intelligent tunnel construction methods will become the mainstream of the times,and TBM construction will become a new development direction in tunnel construction and gradually occupy a dominant position.How to make TBM tunneling equipment work well,quickly and safely under complex geological conditions is an important problem faced by TBM engineering.Aiming at the problem of interaction mechanism and classification constraint optimization of TBM tunneling parameters,this paper studies the interaction mechanism of TBM rock machine parameters by means of engineering field data mining,simulation tunneling test research and numerical model,and transforms the complex interaction mechanism between parameters into mathematical formula,and constructs the tunneling parameter prediction model based on tunneling loading rate.Based on the interaction mechanism of rock mechanics parameters,a classification identification method of surrounding rock drivability suitable for TBM tunnel is constructed.Based on the prediction model of tunneling parameters and classification identification method of surrounding rock,the optimization method of TBM control parameters classification constraints are constructed,and the optimization effect of the optimization method is verified.The main achievements are as follows:(1)Through data mining,the interaction mechanism among tunneling control parameters,tunneling dynamic parameters and rock mass parameters is obtained.Combined with the requirements of TBM simulation tunneling test,the TBM simulation tunneling system and its supporting facilities are developed and designed.Combined with the relevant data of engineering investigation,the proportion test of similar materials in model test is carried out,and the proportion of similar materials in simulated tunneling test is determined.According to the correlation study of the field tunneling data,the simulation tunneling conditions for studying the interaction mechanism of different tunneling parameters are formulated,and the thrust and torque data of tunneling in different strength materials with different penetration and different speed conditions are obtained.The thrust and torque data obtained from the simulation tunneling test are compared with the calculation results of the widely used CSM model,and the matching degree of the mathematical expressions of the complex interaction mechanism among the tunneling control parameters,tunneling dynamic parameters and rock mass parameters in the CSM model is verified.(2)In view of the defects of the widely used CSM model in practical engineering and simulated tunneling test,the optimization content of TBM tunneling parameter prediction model is determined.Based on the research and analysis of rock breaking tunneling mechanism of rolling cutter,this paper studies the parameter correlation of tunneling cutter speed,puts forward the theory of tunneling loading rate of cutter speed,and deduces the relevant calculation formula.The numerical simulation of rock breaking by TBM rolling cutter is carried out,and the particle contact model used in TBM rolling cutter simulation is compared and selected,and the meso parameters are calibrated accordingly.PFC2D software is used to model and simulate the stress during the whole process of rock breaking when the rolling cutter intrudes into the rock.According to the simulation test requirements,different simulation conditions are formulated.The simulation results of rolling cutter forward force under different tunneling speeds under different surrounding rock strength conditions and rolling cutter penetration conditions are obtained.The simulation results are used as the basis to build the prediction model of TBM tunneling parameters.Based on the theory of tunneling loading rate proposed in this chapter,the prediction model of TBM tunneling parameters is constructed.Based on the measured data,the applicability of the improved prediction model of TBM tunneling parameters is verified,and the prediction effect of the improved prediction model and the traditional CSM model is compared by using the percentage error.Compared with the traditional CSM model,the prediction accuracy of TBM tunneling thrust and tunneling torque of the proposed model is improved by 22.1%and 14.1%respectively.(3)The control parameters and rock mass parameters under different surrounding rock conditions are statistically analyzed and their distribution rules are obtained.Based on the evaluation index of TBM rock mass parameters,the tunneling classification method of TBM surrounding rock is constructed.Taking the tunneling data of the project site as the data source,the guidance of TBM drivability classification is verified,and the prediction of the guiding range of tunneling control parameters under different drivability levels is obtained.Starting from the interaction mechanism of tunneling dynamic parameters and rock mass parameters,the identification basis of TBM drivable surrounding rock is determined.The modified formula of specific energy is put forward and the validity of the formula is verified.Using tunneling dynamic parameters and rock mass parameters as prediction input parameters,the modified specific energy is fitted and predicted by using artificial neural network algorithm.According to the irregular distribution of data based on engineering database,the identification model is optimized by using RUSBoost algorithm,and the RUSBoost-ANN surrounding rock interface identification model is established.(4)Aiming at the rock breaking effect of TBM tunneling,the simulation tunneling test and intrusion numerical simulation are carried out.The fracture development and rock breaking effect under different surrounding rock strength are analyzed and studied.The critical S/p ratio under different surrounding rock strength is obtained,and the calculation formula of critical S/p value and uniaxial compressive strength of surrounding rock is obtained by data fitting.Based on the classification level of surrounding rock drivability,this paper analyzes and studies the tunneling mode under different strength surrounding rock conditions.According to the constraints of tunneling mode under different surrounding rock conditions,combined with the guidance range of control parameters of each surrounding rock drivability level,the main control parameters and corresponding control parameter constraint range under each tunneling mode are obtained.Based on the prediction model of tunneling parameters,the multi-objective optimization method is adopted to construct the optimization function of tunneling energy efficiency ratio with the goal of faster net tunneling speed and lower tunneling specific energy.According to the tunneling modes corresponding to different tunneling levels of surrounding rock and the control parameter classification constraints of each tunneling mode,the optimization methodof tunneling parameter classification constraints is constructed.Through the analysis of the optimization results of tunneling parameters under different tunneling modes,the optimization effect of the classification constraint optimization method is verified,and the optimization methods of tunneling parameters under different tunneling modes are obtained.The research results of this paper play a vital role in realizing the matching of tunneling parameters under different surrounding rock conditions in TBM construction,the improvement of TBM tunneling efficiency,and the safe and efficient construction of tunnels.It can further enrich and improve the TBM construction conditions.The theory of optimizing tunneling parameters and the grading system of surrounding rock tunneling have important popularization value,and the application prospect is very broad.