Robustness of inter-module connections and steel modular buildings under column loss scenarios

Abstract

This paper investigates the progressive collapse behaviour of laterally braced steel modular buildings under various column removal scenarios. Unlike the conventional building with continuous floor slab at each storey, steel modular building is constructed by connecting individual modules at the corners. The floor slab in each individual module is often discrete and not connected to each other. Therefore, it is critical to check the robustness of the inter-module connections to ensure adequate redundancy for load redistribution under a column loss scenario. Nonlinear static analysis was performed to study the response behaviour and force transfer mechanism of low-to high-rise modular buildings under various column removal scenarios. The results were compared with those obtained from nonlinear dynamic analysis. The dynamic amplification factor used in the nonlinear static analysis was shown to overestimate the displacement response of the modular building structure under column loss events. The effect of column removal on the inter-module connections was studied for modular steel buildings of 5- to 30-storey height. Design implications related to minimum tie force requirement and its effect on inter-module connection were discussed.