Parametric evaluation of seismic performance for high-rise modular buildings with RC walls: Connections and behaviour factors

Despite the rapid development and application of modular buildings, the structural behaviour of high-rise modular buildings has not been well understood, particularly some key design parameters, including the force and deformation distributions within modular buildings, as well as behaviour factors used for the seismic design, require further investigations. To address these problems, this paper examines the seismic behaviour of modular buildings through a 20-storey prototype building with reinforced concrete structural walls. The detailed numerical model is first developed to represent the modules, reinforced concrete walls, connections, and other key structural elements. Typical dynamic characteristics and plasticity mechanisms of such modular buildings are then evaluated through modal analysis and nonlinear static pushover assessments. Subsequently, a series of parametric studies are undertaken to further investigate the force and deformation distributions within modular buildings when using different connection properties, as well as the possible use of specific behaviour factors in design and the effect on the structural performance. The results demonstrate that the properties of connections show a notable effect on the distribution of lateral drifts over the height, while the effect on the distribution of base shear between modules and RC walls is limited. Design assumptions associated with the inelastic performance of the reinforced concrete walls are also shown, through representative incremental dynamic analysis (IDA), to play a key role in the seismic behaviour. Finally, a hazard-based approach, which can be used for practical assessment and simplified code-based evaluations, is highlighted and discussed.