Response of reinforced concrete columns impacted by tsunami dispersed 20′ and 40′ shipping containers

One of the major issues associated with structures located in the tsunami inundation zone is impact of massive objects carried by the tsunami flow. Characterization of forces and assessment of damage to structures due to such impact loads are vital for the design of buildings used for tsunami evacuation purposes and other important structures located in inundation zones. In the present study, numerical investigation of reinforced concrete (RC) columns impacted by shipping containers dispersed by a tsunami is carried out. Two types of general purpose standard shipping containers which are widely used for maritime freight transport impacting on RC columns with square and circular sections are considered, using high-fidelity finite element models. A series of container-column impact analyses is carried out, and damage to the column is evaluated by means of a damage index characterized by degradation of axial load carrying capacity. This study shows that columns in low-rise RC buildings located in tsunami inundation zones can be severely damaged due to dispersed shipping containers. The peak impact force obtained in this study is used to propose equations for impact duration and effective contact stiffness that could be useful when revising existing design guidelines.