| In recent years,the shield construction method has become more and more widely used in urban tunnel engineering.The edge cutter is one of the main components of the shield cutter head system,and the research on the rock breaking characteristics and layout methods are of great significance to improve the shield construction quality and efficiency.This paper is based on a large amount of literature at home and abroad,and combined with the actual engineering,established a numerical simulation model of edge cutter rock breaking.Analyzed the significance of the influencing factors of rock breaking efficiency by orthogonal test method,and proposed the optimal arrangement of edge cutter.The specific research work is as follows:1.According to the installation position of the cutter,it is divided into the center cutter,the front cutter and the side cutter,and on the basis of the prediction model of the rock breaking force of the frontal cutter,the theoretical calculation model of the vertical force,the rolling force and the lateral force of the edge cutter is given in consideration of the influence of the angle of the edge cutter installation.Meanwhile,it is drawn a calculation method of rock breaking volume of edge cutter based on the concept of specific energy consumption of rock breaking,and analyzed the influencing factors of rock breaking efficiency.2.Taking a shield cutter head of Chengdu Metro engineering as an example,determined the material and dimension parameters of cutter and rock mass,and used ABAQUS finite element analysis software to establish numerical simulation model of rock breaking for #29-#32 side cutter.Compared the simulation value with the theoretical calculation value of rock breaking force,and the results indicated that the simulation value is basically the same as the trend of the theoretical value,and the calculation results indicated that the energy consumption of the cutters in the edge of the cutter head is larger than that the energy consumption of the cutters in the center of the cutter head,the result is in conformity with the actual situation of the project,validated the feasibility of numerical simulation.3.Based on the edge cutter rock breaking simulation model,the variation law of the rock breaking efficiency under the single factor of the blade width,edge angle,installation inclination angle and radius of the circular arc of cutterhead was studied,and the orthogonal test method was further studied.The orthogonal test method was used to study the influence of the multi-factor comprehensive effect on the rock breaking efficiency.The application of SPSS software to obtain the installation inclination was the most significant factor.Based on this,the optimal inclination angle of the edge cutter was optimized.The optimal inclination angle of the first edge cutter was 7°,and the remaining cutters was arranged in descending order of inclination angle.The simulation verified that the overall specific energy consumption after optimization was reduced by 12.17%.4.The installation position of the edge cutter is rearranged on the basis of the installation inclination optimization results,and a multi-objective optimization model with the minimum radial imbalance force and the minimum overturning moment of the cutter head as the objective function is established.The particle swarm algorithm is used to perform the optimization.The solution shows that the radial imbalance force is reduced by 15.31%,and the overturning moment is reduced by 19.39%.This result satisfies the tool layout principle. |
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