Seismic performance evaluation of R/C buildings strengthened with externally attached precast reinforced block wall

Abstract

This study proposes a new concept called Precast Reinforced Block Wall (PRBW), which improves and complements the drawbacks of existing strength enhancement seismic reinforcement methods. The PRBW seismic reinforcement method allows residents to continue residing in buildings while seismic reinforcement construction is underway. It minimizes the increase in building weight due to reinforcement and exhibits excellent joint constructability. Especially suitable for reinforced concrete buildings with typical strength-enhancing seismic reinforcement requirements, which typically exhibit non-seismic details dominated by shear failure, PRBW serves as an easily implementable seismic reinforcement method. Using a physical two-story frame specimen based on existing non-seismic reinforced concrete buildings, pseudo-dynamic experiments were conducted to verify restorability, stiffness enhancement, and seismic response displacement control capability of the externally attached PRBW reinforcement system. Finally, nonlinear dynamic finite element analysis was conducted to compare and analyze the experimental results. The research findings indicated that the discrepancy between seismic response loads and displacements obtained from nonlinear dynamic finite element analysis and pseudodynamic experiments was generally within 10 %. Under Korea's Design Basis Earthquake (DBE) level of 200 cm/ s2, the unreinforced reinforced concrete frame experienced shear failure, while the frame reinforced with PRBW seismic reinforcement suffered minor seismic damage. Even under the maximum considered earthquake (MCE) of 300 cm/s2, only moderate seismic damage was expected. This study successfully validated the effectiveness of the newly developed PRBW seismic reinforcement method.