Study On The Matching Relation Of Shield Tunneling Parameters In Pebbly Sand Stratum

With the rapid development of the subway construction, shield construction has been widely applied in the urban tunnel construction. Tunneling parameters control is the key to shield construction, and it’s of great significance for construction safety and efficiency. This paper studied the matching relation of EPB shield tunneling parameters in pebbly sand stratum by the engineering background of south railway station-shenxianshu station section on line 7 of Chengdu Metro. The major contents of this paper are as follows:Firstly, combining with the actual shield construction, selected the key parameters related to tunneling, analysed their characteristics, influencing factors and distribution regularities. Based on the existing shield parameter calculation model, the relational models of shield thrust and cutterhead torque about pressures of soil chamber and shield penetration were built, and then the field data was used to correct the models.Secondly, based on field driving data, statistical analysis of the relationship between the key parameters was made, the regression models of cutterhead torque and shield tunneling speed based on shield thrust, cutterhead rotation speed and pressures of soil chamber were built, the rationality of the mode was tested, and the correlation of the parameters in the model was analyzed.Thirdly, the BP and GRNN network model were built to predict the key tunneling parameters, their inputs were cutterhead torque, shield penetration and pressures of soil chamber, their outputs were shield thrust and shield tunneling speed, and the average error of the models were both less than 5%. Then compared the prediction results of the two models, and selected the BP model to be used for further study on the tunneling parameters configuration.Fourthly, based on the mathematical relationship among cutterhead torque with pressures of soil chamber and shield penetration, and based on the BP prediction model of shield thrust and key tunneling parameters, calculated the rational scope of the parameters configuration. This study may be used for parameters configuration in similar formation.Based on the GUIDE of Matlab2012b, designed the GUI interface for key parameters of shield analyses, it mainly included four functions as importing excavation data, the key parameters variation analysis, the key parameter prediction based on neural network, and then demonstrated the function of each module based on field driving data.