Non-linear Seismic Analysis of Rigging Frame under Heavy Transient Load


Traditional seismic analysis of an unanchored heavy object on a rigging frame had resulted in unrealistically high seismic pull-out reaction loads for foundation design. The objective was to achieve a more reasonable foundation design by realistically estimate the seismic uplift loads.


ENOVA was contracted to solve this problem. The very high foundation uplift forces were as a result of a traditional lateral load design procedure, treating the very heavy object as attached (anchored) to the rigging platform top. However, due to the transient nature of this load, non-linear seismic analyses were performed allowing for separation of the heavy object from the rigging frame, thus eliminating the high uplift reaction loads, hence resulting in a reasonable and accurate foundation design for the rigging frame.