Performance of Bridges in Liquefied Deposits during the 2010-2011 Christchurch, New Zealand, Earthquakes

The performance of road bridges undergoing liquefaction in the foundation soils and substantial lateral spreading during the 2010-2011 Christchurch earthquakes is discussed in this paper. Three, well-documented case studies are presented in detail to illustrate the performance of bridges and their typical damage associated with lateral spreading. The short-span bridges on pile foundations have a very stiff superstructure (deck), which was a key factor in the seismic response of the bridges. It led to a characteristic deformation mechanism for all bridges involving lateral spreading-deck pinning-abutment backrotation with consequent damage to the abutment piles and slumping of the approaches. Overall, road bridges performed relatively well in the 2010-2011 earthquakes compared to other engineering structures, despite the high seismic demands including substantial liquefaction and large kinematic and inertial loads due to spreading and strong ground shaking, respectively.