Study on the effect of subway construction on adjacent architectural heritages and protection measures

The construction of the subway threatens the safety of adjacent architectural heritages. This study investigates the effect of subway foundation pit excavation and train-induced vibrations on adjacent architectural heritage through a case study of the City Square Station in Shaoxing. A three-dimensional numerical model was established by MIDAS GTS. During the excavation of the foundation pit, it is indicated that settlement was primarily concentrated within the pit, the maximum settlement is 2.06 mm. The pagoda exhibits a maximum global tilt of 0.0025° and a local tilt of 0.11‰, which are less than the threshold. However, within the deep soil influence zone near the pagoda, surface uplift occurred within 1-11.43 m from the foundation pit, followed by settlement. The maximum principal stress and shear stress primarily appeared on the eastern side of the foundation base. Under train-induced vibration, the maximum displacement and acceleration of the pagoda increase from the base to the spire due to the peak acceleration distribution, modal amplification effects, structural mass and stiffness distribution and dynamic inertial effects. To prevent the damage of the Dashan Pagoda, protective measures should be taken, such as optimization of pit support structures, vibration reduction and isolation, structural strengthening.