The Study On The Construction Parameters Optimization Of Shield Machine

As an advanced tunnel construction technique, shield tunnel is widely used in massive tunnel projects across our country. The shield construction parameters such as jack pressure, advanced speed, rotation speed of the cutter, grouting quantity have great influence on the quality and progress of the tunnel construction, which play an important role in safety construction, working efficiently, setting good images and serving society.Therefore, this paper made a further study on the optimization of shield construction parameters. First of all, introduced the research background and development situation of the shield tunnel construction. The main structure of the shield machine, mechanism of earth pressure balance shield and ground surface settlement caused by shield construction have been studied in detail. Based on the real tunnel project, the orthogonal test has been used in the optimum matching and sensitivity analysis for the shield construction parameters. Then established BP neural network and adaptive neural fuzzy inference system(ANFIS) forecasting models.The important construction parameters of shield machine and the current settlement data were treated as the input and settlement data of the next stage were seen as the output. The forecasting model is trained by the shield construction parameters and the settlement data. Then, predicted the surface subsidence caused by shield construction,when the training error reached the goal. The predicted results and the actual data were compared and analyzed, which drew the conclusion that the application value of ANFIS is better than BP neural network in prediction of ground surface settlement caused by shield construction. Method combining neural network and fuzzy inference system is proved to have more prospects for development in the prediction of ground subsidence.Based on subsidence prediction model of ANFIS, the relationship between the important shield construction parameters and settlement data was discussed in detail.The relationship between each of the shield construction parameters and settlementdata was discussed respectively. The common influence which the shield construction parameters have on ground settlement were analyzed as well. Finally, came up with reasonable setting rang of the shield construction parameters.The study on the relationship among the shield construction parameters and optimum matching is relatively delayed in our country. The research on the parameters optimum and surface settlement control still stays in the stage of experience. The issue summarized the regulation between the shield construction parameters and surface settlement in typical geology. Then,made scientific settlement forecasting according to the state of shield construction parameters. The excavation face kept stable and the ground surface settlement was reduced by the means of parameters optimum.It was proved to have good guidance in shield construction.