ROBUSTNESS ANALYSIS OF INNOVATIVE CONNECTIONS FOR POSTAND-BEAM MASS TIMBER BUILDINGS

The design of structural robustness and the prevention of disproportionate collapses in mass timber buildings are becoming relevant considerations due to the increasing height of these buildings. Despite the number of multistory timber buildings has rapidly increased during the last decade, current codes lack specific guidance on mitigating disproportionate collapse. The paper, supported by ROTHO BLASS SRL., focuses on characterizing innovative beam-to-column connections with slotted holes to facilitate structural assembling, ensure hinged structural and catenary behavior under large deformations, particularly in scenarios involving column removal. The research unfolds in three stages: 1) Experimental characterization of the connection's constitutive laws; 2) Parametric study varying beam and slotted hole lengths referring to a simplified 2D post-and-beam subassembly virtual test; 3) Robustness analyses of a 3D post-and-beam archetype building under column removal scenarios using Alternative Load Path Linear and NonLinear Analyses. Results indicate that slotted holes, proposed in the innovative beam-to-column connections, enhance the structural robustness facilitating effective activation of Alternative Load Paths such as catenary effects. Finally, structural robustness of a 4-storey post-and-beam building assembled using the proposed innovative beam-to-column connection was numerically analyzed considering Alternative Load Path Linear and NonLinear analysis scenarios.