The Decision Method Of The Tbm Operating Parameters Based On The Ploybasic Constraint And Objective Optimization

Tunnel boring machine(TBM)has become the main equipment in tunnel and underground engineering construction because of its advantages of high excavation efficiency,small disturbance to surrounding rock,high quality of tunnel completion and strong safety.However,the selection and adjustment of TBM operating parameters in the past mainly rely on human experience.It is difficult to adjust and match with the change of geological conditions in time.The main operating parameters of TBM often do not match and adapt to the rock conditions,which lead to slow excavated speed,sharp increase in construction cost,abnormal wear of cutter head and cutter,even jamming,machine damage,engineering accidents and other serious consequences.Therefore,the research on optimization method of TBM operating parameters is of great significance for ensuring TBM safe,efficient and low-cost excavation,and has become a research hotspot in the field of international TBM construction.At present,there are some tunneling optimization methods or TBM auxiliary construction software in the field of TBM.The main principle is to mine,learn and refine the historical excavation data and experience,and then guide the selection of TBM operating parameters,which promotes the development and progress of TBM intelligent control and decision technology.In recent years,with the improvement of TBM tunneling efficiency,energy consumption,cost and other main performance indicators as the goal,through the construction of mapping model and multi-objective dynamic optimization,the optimization decision of main operating parameters such as revolution per minute of cutterhead and penetration has become a new direction in the field of TBM intelligent control and decision.The advantage of this method is that,considering the laws of large sample historical data and the physical and mechanical characteristics of TBM tunneling,the mapping relationship model and optimization objective function of TBM operating parameters and performance indicators are constructed,and the optimization decision under the mapping model and optimization objective control is realized.It improves the scientificity and reliability of TBM operating parameter optimization decision in principle.Based on the above understanding,this paper puts forward the idea and implementation method of TBM operating parameters optimization based on multi-source prior information and mechanical constraints.The innovative principle is to introduce multi-source information,such as rock strength,integrity and abrasivity are introduced,as well as geometric shape of muck information and cutterhead vibration signal,which affect TBM tunneling performance.Through the research of rock breaking law and large sample data mining,the rock machine mapping model of TBM is constructed.Then,taking the parameters such as cutterhead thrust,torque and conveying capacity of the belt as mechanical constraints.Taking the lowest construction cost as the optimization objective,the optimal decision of operating parameters such as revolution per minute of cutterhead and penetration is realized,which has been successfully verified in practical engineering.The main research work and achievements of this paper are as follows:(1)Research of the mapping of rock and mechine parameters based on rock breaking numerical simulation and linear cutting test.Firstly,rock failure and the cutter load under different rcok uniaxial compressive strength are studied by theoretical methods such as numerical simulation and linear cutting test.Then,the mapping law between the rock mass strength and cutting parameters,such as penetration,cutter spacing and cutter load is extracted by regression analysis method for the numerical simulation and cutting test results.The rock-machine mapping relationships with penetration,cutterhead thrust and torque are constructed respectively.The mapping law obtained will be used as important prior information and constraint conditions in the construction process of TBM rock and excavationg parameter mapping and operating parameter optimization model.(2)Bidrived rock and excavationg parameter mapping construction based on physical law and data mining dual drive.Compared with traditional mapping based on data mining,the results of dual drive rock-machine mapping are less affected by data quality,lower risk of over-fitting and higher universality.By introducing the rock-breaking physical rules in deep neural networks as constraint,the dual drive rock-machine mapping is established.According to the known rock-machine parameters,muck and vibration information,the key tunneling indexes such as cutter life,thrust,torque and the conveying volume of the belt can be calculated.The mapping of rock and mechine are used as objective function and constraints of the optimization model of the TBM operating parameters.(3)The optimization method of TBM operating parameters based on multiple constraints and objectives.Firstly,combining the established dual drive rock-machine mapping and the bearing capacity limit of several TBM mechanical structures,constraint conditions of penetration per revolution,thrust,torque,and conveying volume of the belt,and then the feasible region of operating parameters optimization is obtained.At the same time,taking the optimization of TBM construction cost as the target function,the construction cost mapping including penetration rate and cutter life are constructed,which is used as the objective function of the optimization model.By using construction cost mapping and operating parameters to optimize the feasible region,the combination of operating parameters with the lowest construction cost can be obtained.(4)The engineering verification of TBM operating parameter optimization method.The TBM operating parameter optimization model is verified by two methods of field test data deduction and field driving test.First of all,based on the Hangzhou second water supply channel project,the operating parameters of 50 groups of field measured data samples were optimized.After optimization,the total cost of excavation decreased by 11.1%.Then,a section with a total length of 400 meters and high similarity of rock mass conditions is selected to compare the operating parameters and construction costs adopted in the model optimization and driver control section.It is found that the total cost is reduced by 10%after optimization,and there is no construction accident in the model optimization section.It is proved that the optimization method of TBM operating parameters based on multiple constraints and objectives is reasonable and effective.