Simulation And Stress Uniformity Analysis Of Boots In Contact With The Surrounding Rock Of New TBM

The supporting mechanism is the key part of TBM continuous excavation operation,and boots is the key components of support mechanism.TBM and the working face are separated in the process of tunneling,supporting system extends out of boots to support the rock,and propulsion is driven by the friction between boots and rock.On the basis of the problems such as the supporting surface is not supported,the surface of rock is easy to fall off,ground pressure is not uniform,the parts are easy to wear and so on,once boots are broken,they will seriously affect efficiency and economic benefits of the project.Then model for development of the scale experimental prototype boots need to provide enough support,to meet the thrust and torque demand,how to improve boots and rock contact surface uniformity,optimize the rational allocation of ground pressure,improve supporting reliability and support ability,which is the key to work efficiency.Therefore,it is very important to study analysis of simulation and uniformity.Based on the model of TBM scale experimental supporting boots as the object,focusing on these questions,carrying out the following research:1.Research of scale experimental prototype based on the development of universitiesand enterprises,put forward the theory and design method of the test bench,which laid foundation for the completion of the new mechanism of principle prototype design;Providing a reference for design of a new type of boots based on the advantages and disadvantages of thevarious types of boots;Based on the research of rock and contact mechanics,stress state of rock and basic method to solve the problem of contact between boots and rock are put forward.2.Drawing the TBM test model by SolidWorks,getting structural parameters of the internal mechanism,and analysing boots and rock stress,describing internal structure of TBM and rock interaction force transfer path,analyzing general expressions of displacement and stress by the axisymmetric elastic mechanics of stress state,determine the circle of influence is 3R0~5R0,through the establishment of boots and rock micro contact mechanics model,getting the calculation formula of contact pressure,and sketches of the finite element contact model of three kinds of loads is drawn.3.Based on the three finite element contact model of boots and rock,theoretical contact,intermediate clearance contact and bilateral clearance contact,Using three kinds of bearing load of Abaqus on the theory of the contact model of finite element analysis,They are programed summarizes for stress and displacement distribution characteristics law of boots and rock contact surface by MATLAB,Comprehensive analysis influence degree of the three kinds of bearing load,The stress and displacement equipotential lines are plotted to provide the basis for the analysis of the contact surface of rock.4.The article puts forward the ground pressure uniformity index lambda,The higher the evaluation index,the greater the propulsive force,and the higher the security of support under the given support conditions,and the proportional relationship.Then stress and displacement of the contact surface of the three kinds of contact types are analyzed and compared,to get the scope of the optimal load difference.