Research On Optimum Control Of Shield Tunnel Intelligent Correction

With the increasingly severe problems of urban traffic congestion and shortage of land resources,the construction of subway tunnels by shield method and the utilization of urban underground space have become an important measure to alleviate urban traffic pressure.When the shield machine is being excavated,it is affected by the uneven geological distribution and the mechanical equipment of the shield machine.The deviation of the tunneling trajectory from the tunnel design axis is very common.It will extend the construction period and affect the safety of the ground building and the subway.Accurate and fast shield attitude correction has become an important issue that needs to be solved in the construction of subway tunnels.In this paper,aiming at the shortest reorientation trajectory,the research on optimum control of shield tunnel intelligent correction is carried out.The main contents are as follows:(1)Analyze the influencing factors which affecting the correction radius of the shield machine,and clarify that the correction path is the shortest when the minimum correction radius method is used.(2)Taking shield machines with 16 sets of hydraulic in 3:4:4:5 area as the research object,according to the relationship between the soil resistance torque and the thrust torque of the hydraulic cylinder during the correcting of the shield machine,a mathematical model for shield correction in soft soil layers was established in order to obtain the shortest correcting trajectory.(3)In order to improve the accuracy and speed of shield correction,an improved artificial bee colony algorithm is proposed to optimize the correction model.Using Cat mapping combined with differential variability to increase the population diversity and improve the search strategy of the algorithm.The convergence speed and optimization precision of the artificial bee colony algorithm are improved.(4)Taking the minimum variance of the hydraulic cylinder thrust of the shield machine as the optimization target,the improved artificial bee colony algorithm is used to optimize the correction model and compare it with the shield correction data of Zhengzhou Metro Line 4.The results show that the solution results are close to the artificial correction data using the minimum correction radius method.The improved artificial bee colony algorithm is used to optimize the shield correction model,which realizes the accurate correction of the shield machine in the subway tunnel construction,and can provide auxiliary decision for the shield correction.It is significant to reduce the construction risk of subway tunnel construction,shorten the construction period and improve the operation safety of subway tunnels.