Seismic design and performance of self-centering precast concrete frames with variable friction dampers

• Published in: Engineering structures Vol. 245; p. 112863
• Main Authors: Huang, Linjie, Clayton, Patricia M., Zhou, Zhen
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.10.2021; Elsevier BV
• Subjects: Beam-column connections; Design; Design modifications; Design parameters; Drift; Earthquake dampers; Earthquakes; Frames; Friction; Geological hazards; Ground motion; Hidden corbel; Mathematical models; Numerical models; Parameter modification; Performance-based seismic design; Post-tensioning; Precast concrete; Reinforced concrete; Seismic activity; Seismic design; Seismic hazard; Seismic response; Seismic zones; Self-centering; Stiffness; Variable friction dampers; Performance-based seismic design; Self-centering; Beam-column connections; Variable friction dampers; Precast concrete; Hidden corbel
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2021.112863

•New self-centering precast concrete frames with increasing post-decompression stiffness.•Seismic design method considers the changing stiffness of variable friction dampers.•A method to mitigate the concentration of story drifts was proposed.•A method to mitigate detrimental higher mode effects was proposed. This paper presents the numerical investigation of the seismic performance of post-tensioned self-centering precast concrete (SCPC) frames with variable friction dampers (VFDs) and hidden corbels (HCs). The VFDs are characterized by the combination of flat and grooved plates, where the friction forces change as the connection deformation increases, which enables designs to meet target seismic performance objectives at different seismic hazard levels. Theoretical and numerical models for the connection are proposed based on connection geometry, and a performance-based seismic design approach for the SCPC frames is outlined to meet target performance objectives at two common seismic hazard levels, the design basis earthquake (DBE) and the maximum considered earthquake (MCE). SCPC frames for a six-story prototype building located in a high seismic zone in California were designed using this procedure. Three frames with HC-VFD-SPSC connections were designed using various methods to mitigate concentration of drifts in the first story, and one frame was designed with conventional constant friction devices (CFDs) for comparison. Nonlinear time-history analyses were performed for these different designs using two sets of ground motions representing the DBE and MCE seismic hazard levels. The analysis results indicate that the frames with the HC-VFD-SCPC connections achieved the target performance objectives. The proposed approaches of modifying post-tensioning and VFD design parameters or column stiffness in the first story were effective in mitigating the concentration of drifts. Additionally, through comparison with the results of the frame with CFDs, it was found that the VFDs are effective in decreasing overall drift demands at the MCE level, as well as mitigating detrimental higher mode effects observed in SCPC frames with CFDs.