Simulation of lateral-spread induced piled bridge abutment damage mechanism

The Avondale Road Bridge in Christchurch, New Zealand was extensively damaged due to liq-uefaction and consequent lateral spreading induced by the Canterbury earthquake sequence (2010-2011). The deck acted as a prop, forcing the abutments to rotate around the deck-abutment connection, causing extensive plastic hinging within the foundation piles and also resulted in extensive settlement in the backfill. In order to further study this observed damage mechanism, key bridge parts were modelled at 1:50 scale including piles made of damageable model reinforced concrete (RC). The soil model was modelled on the layered profile of the south abutment, where the most severe damage was manifested. The model was designed, manufactured, assembled and tested in the University of Dundee (UoD) centrifuge facility. The centrifuge test validated the observed damage mechanism, including the pinning effect of the deck, abutment rotation and backfill settlement, providing a benchmark for future testing of possible retrofit solutions