A comprehensive soil-structure interaction analysis for assessing seismic resilience of multi-storey buildings in bengkulu under variable seismic waveforms

This study evaluates the seismic performance of the four-storey Integrated Laboratory Building of the Faculty of Engineering, University of Bengkulu, using an integrated approach combining site-specific seismic soil response analysis and three-dimensional structural dynamic analysis. Three representative earthquake records, i.e., the Bengkulu–Mentawai Earthquake (M w 8.6), the Chi-Chi Earthquake (M w 7.7), and the Coyote Lake Earthquake (M w 5.7), were selected to capture variations in source mechanisms, frequency content, and ground-motion characteristics. Results show strong amplification in the upper clay layers, with surface PGA values reaching 0.211 g, 0.223 g, and 0.298 g, respectively. The amplification factor at the site is generally observed to vary from 1.4 to 1.8. Spectral acceleration at the ground surface exceeded SNI 1726:2019 design spectra in the medium-period range, indicating increased seismic demand on mid-rise structures. Time-history-based structural analysis revealed significant increases in internal forces, particularly in critical elements, including the curve, which exceeded allowable stress ratios. These findings highlight the importance of incorporating site-specific soil effects and ground-motion characteristics in seismic evaluation and support the need for targeted retrofitting strategies to improve building resilience in earthquake-prone regions.