Disproportionate collapse prevention of CLT platformtype buildings

Without additional design considerations, such as structural robustness, the failure of a building’s structuralelement can develop into a progressive and/or disproportionate collapse. The existing requirements given ininternational guidelines for preventing disproportionate collapse are generally not practical and uneconomicwhen applied to multi-storey cross-laminated timber (CLT) buildings in platform-type construction. This papersummarises recent research and improved approaches developed to meet structural robustness for such buildings.To ensure alternative load-paths using simplified linear elastic analytical procedures, an improved methodusing engineering mechanics was derived for CLT buildings in platform-type construction to aid in quantifyingconnection tie forces between structural components. Using advanced nonlinear dynamic analyses, the behaviourof two case-study buildings under element removal scenarios are studied: i) 12-storey with CLT floor and wallsystem; and ii) 9-storey flat-plate CLT floor system point-supported on glulam columns. Finally, in a nonlinearpushdown analysis of a platform CLT bay to characterise the resistance mechanism of the floor and wall panels,four different alternative load-paths are evaluated. The presented findings can support the design of multi-storeyCLT buildings in platform-type construction to ensure structural robustness.