Experimental Study of the Seismic Response of Container Cranes

As container traffic increases, ships and the cranes that serve them also continue to grow. The larger size and mass of modern container cranes makes them more seismically vulnerable then their predecessors. Container cranes are essential for port operations, and economic losses from their downtime can be substantial. A container crane can be divided into three main sections: the portal frame, a second story and the A-frame. The majority of the response of a container crane to dynamic loading occurs in the portal frame. This study investigates a way to model the container crane without the A-frame, while maintaining the same response in the portal frame. Finite element models of a complete container crane and cranes with modifications to simulate the proper mass and stiffness distribution without the A-frame are created. These results are used to design a large scale model for a shake table experiment that investigates the three failure modes previously observed in earthquakes: derailment, local buckling of the legs, and collapse.