Relationship between ground motion parameters and building damage for 2016 Mw 6.4 Meinong, Taiwan earthquake

This study examines the relationship between ground motion parameters and building damage during the 2016 Mw 6.4 Meinong earthquake in southern Taiwan. We integrate strong-motion recordings from 599 Taiwan Strong Motion Instrumentation Program (TSMIP) stations with a georeferenced dataset of 626 damaged buildings (271 red-tagged, 355 yellow-tagged) in Tainan City. Results show that structural damage began at thresholds of ~150-175 gal for peak ground acceleration (PGA) and ~10-20 cm/s for peak ground velocity (PGV). Regression analysis indicates that PGA correlates much more strongly with building damage (r = 0.98 for red-tagged, 0.81 for yellow-tagged) than PGV (r = 0.46 and 0.26). About 70% of damaged buildings were low-rise (1-3 stories), consistent with resonance effects from short-period ground motions. Local soil liquefaction further contributed to failures in some areas with modest PGV. These findings highlight the dominant role of PGA in assessing low-rise building vulnerability, while PGV remains relevant for high-rise damage. We conclude that both parameters should be jointly considered in seismic impact assessments. This work provides the first quantitative validation of PGA and PGV against Taiwan’s updated red/yellow-tagged building damage classification, establishing a benchmark for future risk evaluation.