In the process of slurry balance shield excavation

the thrust force is difficult to determine and the fluctuation is complicated. In light of this problem

the resistance in the process of shield advance is analyzed systematically; and then the component and calculation method of the resistance are determined. The calculation formula of friction between shell and surrounding soil is modified. And the composition and working principle of slurry water balance shield thrust system are analyzed. Basing on the static model of shield thrust

a single degree-of-freedom dynamic model is established. According to the principle of energy conservation

the equilibrium differential equation of the system is established; and then the formula of nonlinear kinetics is derived. Based on the above formula

the change trend and fluctuation of shield thrust are summarized and the optimal distance of hydraulic jack is put forward in the process of propulsion. Through the comparison and analysis of the measured data of the thrust force of the Yangtze section of the tunnel at Wuhan metro line 8. It is proved that the formula can be used to calculate the dynamic thrust load of the lining accurately

which is of great importance to the analysis of the internal force of the lining structure.