Assessment of the seismic behaviour of braced steel storage racking systems by means of full scale push over tests

摘要

Pallet racking systems, made of thin-walled cold formed steel profiles, are commonly used to store valuable goods and products in the logistics industry. In service conditions, longitudinal (down-aisle) stability of the racks is provided by the flexural stiffness of the demountable beam-upright column connections and base joints. Rack designers usually prefer to avoid bracings for a full accessibility of shelves from both aisles. However, under seismic conditions, typical rack connections cannot often provide sufficient flexural performance in terms of stiffness and strength, which deems necessary to introduce spine (longitudinal) bracings in the down-aisle direction. Yet the racks can only be braced at one of their two longitudinal planes to allow pallet loading from the aisle, which results in an asymmetric horizontal bearing configuration. This combined with their perforated upright columns, and nonstandard beam-upright and base connections make it even more difficult to estimate their complex global seismic performance. Therefore, full scale experimental investigations are strongly needed in order to understand and quantify the global performance of the braced storage racks, and improve their design for seismic actions.