Performance-Based Seismic Evaluation of Two Five-Story Precast Concrete Hybrid Frame Buildings

The unique features of the hybrid frame, which include minimum structural damage when subjected to earthquake loading and the recentering capability, are the result of using a combination of mild steel reinforcement and unbonded prestressing to establish connections between precast beams and precast columns. Using acceptance criteria defined in terms of interstory frame drift and floor acceleration, this paper presents a multiple-level performance-based seismic evaluation for two five-story precast concrete hybrid frame buildings. The design and analysis of these two buildings, established as the displacement-based and force-based design solutions for a prototype building used in the precast seismic structural system (PRESSS) program, were conducted at 60% scale so that the analysis models could be validated using the PRESSS test data. Despite a difference of 40% in the design base shear, the two buildings satisfied the acceptance criteria when subjected to input motions with intensities less than or equal to that of the design-level earthquake. For input motions, equal to 150% of the design-level earthquake, the building designed using the displacement-based principles did not satisfy the interstory drift limit, whereas the force-based solution provided acceptable performance.