Nonlinear Response History Analyses of NCREE Research Building Extension

Nonlinear Response History Analyses of NCREE Research Building Extension

This paper presents nonlinear response history analyses (NRHA) of the research building extension of the Taiwan National Center for Research on Earthquake Engineering (NCREE). Through the extension, NCREE’s research building becomes a composite structure comprising a strengthened six-story reinforced-concrete (RC) structure and a vertically added seven-story steel structure. A new steel service core was added from the first floor to the roof at the north side of the building. To upgrade the earthquake-resistant performance, novel energy-dissipation devices such as buckling-restrained braces, steel panel dampers, and fluid viscous dampers are utilized. To gain insight into the seismic performance of NCREE’s extended building, PISA3D structural analysis software is used for constructing the numerical model to conduct not only modal analysis but also NRHAs. To conduct these NRHAs, a total of twenty-one sets of historic earthquake ground accelerations are chosen and scaled to fit the Taipei Zone II design-basis earthquake (DBE) spectrum. The scale factors of the DBE range from 2.22 to 6.35. The earthquakes corresponding to the hazard levels of a service-level earthquake (SLE) and a maximum-considered earthquake (MCE) are 0.29 and 1.3 times that of the DBE, respectively. Through the NRHAs using the scaled ground accelerations of three different earthquake hazard levels (SLE, DBE, and MCE), it is found that maximum inter-story drifts are distributed evenly in the longitudinal direction but unevenly in the transverse direction. In the DBEs, the means of the maximum inter-story drift ratios are less than 1.5%, and thereby meet the ASCE/SEI 7-10 limitations of the buildings of the risk III category (e.g., lecture halls). In the MCEs, the means of the maximum inter-story drift ratios are less than 2%, and thereby meet the FEMA 356 performance limitation for life safety. Hence, the seismic performance of NCREE’s extended building is verified to be satisfactory.