Research On Excavation Characteristic Identification And Attitude Control Of Tunnel Boring Machine

Full face hard rock tunnel boring machine(TBM)is a large-scale factory tunneling system for rock excavation,transportation of dregs,support lining and gripper and thrust.TBM mainly consists of cutting system,supporting propulsion system,position adjusting system,dregs transfer system,hydraulic control system,electrical control system,ventilation and dedusting system,drilling and anchor support system etc.The classification of the surrounding rock is highly significant for research and manufacture of the TBM,the surrounding rock quality evaluation and the support design.However,no uniform classification method for the surrounding rock mass has been applied.The forward boring,laboratory testing,field judgment and other means are adopted to existing classification method,which are subjective and time-consuming.The anti-torque of the cutterhead on the rock is transmitted to the left and right torque cylinders during excavation,which is still neglected by the vertical adjustment system currently.It is necessary to propose a new classification method for the surrounding rock mass based on the tunneling parameters and design a high-precision vertical adjustment system.This issue was supported by National High-tech Research and Development Program(863).The classification and identification method based on TBM driving parameters was proposed through the analysis towards the data of the water supply project in the central Jilin Province.A vertical adjustment strategy with angle closed loop was designed.A 2.5m TBM test rig of gripper and thrust system with the capability of simulating different surrounding rock loads and TBM attitude adjustment was designed.The main research contents are as follows:1.Based on 42,000 sets of data from the real field,several factors like the total thrust,penetration,cutter torque,pressure of gripper cylinder,left and right gripper displacement,the difference between left and right gripper displacement in different surrounding rock are discussed respectively.The result shows that the maximum value of TBM total thrust has a positive relationship with the type of surrounding rock in a certain period of time.The effect of the change of rock type on the cutter torque is not obvious.The penetration varies greatly with the change of the surrounding rock,which reflects the changing trend of surrounding rock.And the relationship between the displacement of left and right boots and the type of surrounding rock is not shown.2.After twice transformation towards TBM tunneling parameters,the Field PenetrationIndex(FPI)and Torque Penetration Index(TPI)are defined.The field penetration index can reflectthe load characteristics of rock mass to a certain extent.The TBM tunneling characteristic index isdefined.The multiple regression method is used to solve the undetermined coefficients and the BPneural network method is used to identify the characteristic value of surrounding rock load.3.Due to the reaction of the surrounding rock on the cutter head,anti-torque is transmitted tothe main beam,leading the displacement deviation of the left and right torque cylinder in existingvertical adjustment system and the main beam rolling.A high precision vertical steering hydraulicsystem is designed,and a synchronous control strategy with angle closed-loop is proposed to ensurethe acccuracy of displacement control of the left and right torque cylinders.The simulation byAMEsim and Simulink shows that the proposed method can reduce the displacement deviation ofthe left and right torque cylinders of the existing adjustment system and improve the pitch angleadjustment accuracy.4.The hydraulic system and monitoring system of 2.5m diameter TBM gripper and thrust testbench are designed.The simulation systems of torque load,thrust load and cutterhead restraint aredesigned to simulate the load of different surrounding rock.The design of the cooler is carried outto reduce the heating value of the torque load simulation system,and a vertical adjustment systemwith pressure compensation and balance valves is designed.The design of the monitoring systemis completed,including hardware selection,PLC programing,human-computer interactioninterface design and so on.