Design and testing of a timber-steel hybrid beam string structure

Abstract This paper discusses the design and construction of the gymnasium at Musashino University’s Musashino Campus in Tokyo, Japan. The project integrates a hybrid section combining steel and European redwood, addressing the need to blend the building harmoniously with the campus’s lush greenery. A key design challenge was to incorporate wood as a significant structural element while adhering to Japan’s stringent fire regulations. The solution involved a T-shaped steel section with a timber sandwich, preventing steel web buckling and achieving superior structural performance. Approximately 50 cubic meters of timber were used, enhancing both the aesthetic appeal and the environmental sustainability of the project. The hybrid approach allowed the beam string structure to meet design load requirements effectively. Full-scale testing confirmed the structural integrity and load-bearing capacity of the hybrid section, matching those of a full steel section.