Advanced seismic design approach for automated rack supported warehouses

Automated Rack Supported Warehouses (ARSW) are huge steel buildings offering storage solutions. When the number of pallets is relevant and the daily handling operations are numerous, they offer the best options for goods flow management and space optimization. They constitute the direct upgrade of traditional pallet racks, but, differently from these, the shelves constitute the warehouse's structure, besides bearing pallets. To follow the fast-evolving market request, ARSWs acquired most of the racks' structural features without being supported by a specific regulatory framework. This lack brought with time to relevant catastrophes that highlight the lack of knowledge that concerns these structures. The absence of proper prescriptions to be followed to the design of ARSWs results, in most cases, in the adoption of the same guidelines defined for traditional steel racks (UNI EN15512 (2009) and UNI EN16681 (2016)) and to the adoption of the same structural choices and technical solutions. In this framework, this PhD thesis shows a possible new approach for the design of ARSWs. In particular, based on an accurate evaluation of safety levels and the design strategies now adopted in current practice, this new design approach focuses on seismic conditions, dealing specifically with Double-Depth structural typology. This approach is defined by assuming a dissipative behaviour and evaluating different and possible yielding patterns as an alternative to the global collapse mechanism, where the whole structure is involved. The optimization of the cost-benefit ratio is always considered as one of the design goals. The study and the analysis of ARSWs are widely performed inside the European research project “STEELWAR: Advanced structural solutions for automated STEEL rack supported WARhouses” funded by the Research & Innovation, Research Fund Coal and Steel (RFCS) and coordinated by the University of Pisa.