Abstract:
Taking the Shenyang utility tunnel project in water-rich strata as the research background, which is ex? cavated by a EPB shield machine, the vertical displacement and horizontal displacement of the ground surface caused by the EPB shield tunnelling are monitored, and the displacement development law is analyzed. According to the actual measured displacement data, the PSO-BP parameter inversion analysis method is established based on the particle swarm optimization algorithm. The displacement inverse analysis program is compiled using Fortran language, and the parameter inversion is performed using orthogonal design and ABAQUS numerical calculation method. Considering the effects of static earth pressure, active earth pressure and passive earth pressure on the working face stability, the limit supporting pressure on the shield-driven utility tunnel face is analyzed according to the inversed soil parameters. The results show that the PSO-BP parameter inversion analysis method is a feasible and effective method. When the supporting pressure ratio is 0.4, the working face is in the limit state; and with the decrease of the supporting pressure ratio, the ground surface settlement maintains an increase trend. When the effect of groundwater is considered, larger supporting pressure should be needed to ensure the stability of the working face;and the working face is in the limit stat when the supporting pressure ratio is 0.6.