Simulation-Hybrid Approach to Protecting Aging Bridges against Nearby Tunnel Excavation

Abstract

Numerous urban infrastructures (e.g., bridges, roads, tunnels, pipes) are aging and vulnerable to external disturbance, particularly for tunneling excavation in densely built areas. A simulation-hybrid approach for protecting aging bridges against adjacent excavation-induced damages is developed. The potential safety risk of an existing bridge is assessed based on spatial neighbor relation and bridge health condition. A reasonable balance between project safety and budget constraints is reached, where the magnitude of the assessed risk is essential to the numerical analysis applied. A real tunnel project in the construction of Wuhan Metro Line 2 (WML2) in China is used to demonstrate the feasibility and applicability of the developed approach. The foundation pit of Xunlimen Station is 1.25 m away from the nearest pier of Wuhan Light Rail Line 1 (WLRL1). The impact of the foundation excavation on adjacent bridge piers is further analyzed, and relevant control measures are then proposed. The novelty of this research lies in the consideration of both hazard (spatial neighbor relation) and vulnerability (bridge health condition) characteristics for the development of responsive strategies for protecting aging bridges against excavation-induced damages.