Modeling of the thrust and torque acting on shield machines during tunneling

The paper analyzes the total load in the shield tunneling process. The cutterhead load is the most complicated component which provides a real-time response to geological conditions and operating states. This study calculates the normal and tangential loads on cutterhead by decoupling the cutterhead-soil system on excavation face. Then a comprehensive consideration is made of the influences of the overburden, the soil cutting, the chamber support, and the friction between the shield and the soil on loads. This study establishes a predicting model for the total load that fully reflects the influences of geological, operating, and structural parameters. The model is applied into two cases. Its effectiveness is verified by comparing the load calculated by the model, measured during tunneling and predicted by the Krause empirical model. The paper provides a reference for load designs and parameter controls during construction.