Analysis of Impact of Shield Tunnel Construction on Xi'an Bell Tower in Loess Strata

The loess has a higher strength in the dry condition and strength reduction in water condition, this special engineering geological property brings serious impact on the metro shield tunnel construction in loess strata. Xi'an metro line 2 is the China's first metro shield tunnel constructed in loess strata, it is very necessary to reduce the impact of its construction on the ancient architectural buildings. According with the project of Xi'an metro line 2 passes beneath the bell tower, this paper established the three-dimensional nonlinear finite element model to study the impact of shield tunnel construction on the bell tower reinforced. The results show that, because of the reinforcement effect with swivel-driven piles, the surface settlement caused by shield tunneling is mainly distributed outside the piles and the surface longitudinal settlement curve has an obvious inflection point at the piles. The maximum settlement and tilt of bell tower base caused by shield tunneling satisfies the control standard and the reinforcement effect is significant.