Experimental investigation of innovative modular bidirectional load-bearing and energy-dissipating joints for high-rise modular constructions

Abstract

Modular bidirectional load-bearing and energy-dissipating joints (MBJs) can complete adjacent module connections only by modular bidirectional load-bearing and energy-dissipating connectors (MBCs). Splice plates with high-strength bolts were proposed to implement modular and high-rise modular constructions based on their load-bearing and energy-dissipating functions. The proposed environmentally friendly MBJs are fully bolted joints which can be dismantled rapidly and reused after dismantling. A quasi-static test of a full-scale specimen of MBJ was carried out to evaluate their seismic resistance properties; its initial rotational stiffness, moment resistance, ductility, and energy dissipation were assessed comprehensively, as well as failure pattern, to evaluate its application in a seismic region. For MBJs with double beams and adjacent multiple columns, specialized hinge-loading devices on multiple columns and beams were proposed to implement constraint and loading. The moment capacity of MBJs was also predicted based on a mechanical analysis. The experimental results indicated that the proposed MBJs can reliably connect four modules with the ratio of the designed ultimate moment capacity of double beams Mp, beam to the average ultimate moment capacity Mu 1.183, indicating that the tested MBJs have an excellent capability to develop the full plastic moment capacity of double beams. The hysteresis curves were full and stable, and the average equivalent viscous damping ratio was 0.329. An excellent energy-dissipating capacity was observed. The predicted moment capacities of the MBJs were also verified to be credible. The proposed MBJs, which achieved a strong-column weak beam, were inferred from the failure patterns and strain values in the test. The analysis of the ductility factor and inter-story drift ratio indicated the feasibility of MBJs in seismic regions.