Evaluasi Kinerja Global dan Simpangan antar Lantai Struktur Gedung terhadap Gempa Ambon Menggunakan Analisis Pushover

Abstract

Indonesia is located in a region with high seismic activity, making structural performance evaluation necessary to consider the seismic demand corresponding to the building location. This study evaluates the performance of the five-story SOHO Ginza PIK 2 Building, originally planned for Tangerang, when analyzed under the higher seismic demand of Ambon City. The model was developed using ETABS with existing dimensions, gravity loads, and spectrum parameters in accordance with SNI 1726:2019. Response spectrum analysis was performed on the existing model and two column modification schemes, namely column widening on Floors 2–3 and column widening by 100 mm. The model with widened columns that provided the best response was then compared with the existing model through pushover analysis. The performance point was obtained using the FEMA 440 Equivalent Linearization procedure, while the global performance level was interpreted using the ATC-40 drift limits. Under the Ambon spectrum, the maximum displacement of the existing structure in the X direction reached 86.99 mm and exceeded the limit, while the Y direction remained within the limit. Widening all columns reduced the displacement to 62.15 mm in the X direction and 53.26 mm in the Y direction. The global drift ratio at the performance point was approximately 0.014–0.018, within the Damage Control range. However, the interstory drift ratio on Floors 2–4 still exceeded the Life Safety limit. These results indicate that improvements in global stiffness and capacity do not always produce uniform improvements in local performance; therefore, global and local indicators should be considered simultaneously.