Effect of double track tunnel with small distance on existing tunnel deformation

Abstract

MIDSA/ GTS software is used to simulate the double track parallel shield construction. The influence of double track shield construction on the existing tunnel under different small clear distance is studied, and the displacement and plastic zone development law of the existing tunnel are summarized. The analysis shows that the subsequent shield excavation will cause the clearance expansion and vault subsidence of the existing tunnel, and the uplift deformation of the inverted arch and the plastic zone of the surrounding rock of the tunnel will further become larger. When the clear distance is only 0. 8 times the tunnel diameter, reinforcement measures need to be taken.