Haunch connecting techniques in a self-centering modular steel structure connection system

Abstract

High extent of mechanized assembly is one of the development concepts of the modular construction, allowing the full development of its superiority in construction efficiency and quality. The primary focus of this research is to propose novel types of connecting techniques between the haunch brace and the module in the self-centering modular steel structure (SC-MSS) connection system, which horizontally inserts the long through-bolts inside the columns or fixes the sleeve device by bolts around the periphery of the columns to achieve stable and effective connecting performance and well installation convenience at the construction site. The functional mechanism of the traditional and novel haunch connecting techniques are clarified and the seismic performance of the SC-MSS connections with different connecting techniques are investigated due to monotonic and cyclic loadings. Results demonstrate that the strength and stiffness of all connections develop as the similar trend and stable hysteretic responses with satisfactory self-centering capability can be observed. Furthermore, the haunch reaction force is reasonably distributed and effectively transmitted under the proposed connecting techniques, which could control the stress level in the haunch intersection regions of the modules and well protect the key structural members. The mechanical and deformation mechanisms of the haunch connecting techniques are analyzed and some design considerations are provided accordingly for offering the guidance for the engineering design and application of SC-MSS connection systems.