A hybrid coupled wall system with replaceable steel coupling beams for high-rise modular buildings

Abstract

Modular construction has been widely adopted for low-to-medium-rise buildings. However, there are concerns about the wind and seismic resisting performance of high-rise buildings if adopting the modular approach, which inhibit the wider adoption of modular construction in most cities where high-rises dominate. This paper aims to develop a novel hybrid coupled wall system for high-rise modular buildings, which uses replaceable steel coupling beams and precast concrete walls within modules to replace in-situ concrete or steel cores. The wall system is expected to improve not only the productivity of modular construction but wind and earthquake resilience of high-rise modular buildings. A nonlinear finite element (FE) model was developed for a 40-story residential building in Hong Kong using the hybrid coupled wall system. The seismic performance of the hybrid coupled wall system was assessed according to the results of nonlinear dynamic analysis and is compared with an alternative reinforced-concrete coupled wall system. Results show that the developed FE model is capable to predict the nonlinear structural performance of the hybrid and reinforced-concrete coupled wall systems. The two wall systems can provide sufficient seismic resistance for the 40-story building at four intensities of earthquake motions. They have similar seismic responses of wall piers but different seismic responses of coupling beams. The expected damage is very low for both wall piers and coupling beams of the two coupled wall systems even at very rare earthquake motions. The feasibility of the developed hybrid system was also examined in terms of wind load resistance. The results indicate that the system has sufficient capacity to resist the wind load in Hong Kong.