Identification and optimization of energy consumption by shield tunnel machines using a combined mechanical and regression analysis

This paper presents an identification and optimization method for the energy consumption of a shield tunnel machine. The specific energy, defined as the energy consumption to excavate a unit volume of the ground, is a good measure of the working efficiency of a shield machine. A model of the specific energy was created using a mechanical analysis before doing an in-site data regression analysis. The mechanical analysis of the shield-ground system helps decouple the nonlinear multi-parameter problem, and then the nonlinear multiple regression process was conducted using in-site data from a subway project in China. Fairly good consistency between the recorded data and the results predicted by the model using the testing data is achieved. Finally, the influence of the cutting depth per revolution on the specific energy was discussed. The optimal ranges of the cutting depth under different geological conditions were provided to improve tunneling efficiency.