EARTHQUAKE EFFECTS ON LOW PROFILE CONTAINER CRANE WITH SEISMIC ISOLATION DEVICE

摘要

The focus of this research is to evaluate and compare the mechanical behaviour of a big ship to shore low profile container crane subjected to earthquake actions, with and without anti-seismic device applied to it. For this purpose, a specific machine was designed considering different load and geometrical configurations. Subsequently, the earthquake actions were studied. The different acceleration spectrums were established by Italian standards. The anti -seismic device was chosen to limit the crane displacement to not compromise the crane performance due, for example, to the increase of the payload swinging effect. The numerical results show that, for each load and geometrical configurations assumed, the anti-seismic device has a positive effect, it reduces the maximum stress values (about 20%). The dynamical crane behaviour is practically unchanged with the isolation device adopted, it was observed a small reduction of the natural frequencies values and a little increase of the magnitude of the maximum displacement. These results are valid also in case of dynamic action applied to the crane due, for example, to the trolley and payload movement.