ANALISIS PERBANDINGAN KINERJA STRUKTUR BANGUNAN FIXED-BASE DAN BASE-ISOLATION DENGAN VARIASI REDAMAN EFEKTIF ISOLATOR

Abstract

Indonesia merupakan negara yang rawan terhadap bencana kegempaan. Indonesia terletak pada cincin api Pasifik dan di atas lempeng tektonik sehingga berpotensi terjadi gempa bumi yang menyebabkan kerusakan pada bangunan dan infrastruktur. Seiring perkembangan dunia konstruksi, telah dikembangkan berbagai teknologi peredam gempa, salah satunya sistem isolasi dasar (base isolation). Penelitian ini bertujuan untuk membandingkan kinerja struktur dari bangunan konvensional (fixed base) terhadap bangunan base isolation yang divariasikan redaman efektif isolator sebesar 2%, 5%, 10%, 15%, 20%, 25%, dan 30%. Prosedur analisis seismik mengacu pada SNI 1726:2019 menggunakan metode statik ekivalen dan dinamik respons spektrum. Evaluasi tingkat kinerja struktur mengacu pada ATC-40 menggunakan metode statik non-linear pushover. Hasil penelitian ini menunjukkan respon seismik struktur berupa gaya geser dasar, perpindahan dan simpangan antar lantai, serta gaya dalam pada elemen struktural mengalami tren negatif (penurunan) yang terjadi secara non-linear seiring dengan peningkatan nilai redaman efektif isolator. Hasil evaluasi tingkat kinerja struktur menunjukan bahwa penggunaan base isolator mampu meningkatkan level kinerja struktur dimana pada struktur fixed base memiliki level Damage Control (DC), meningkat menjadi level Immediate Occupancy (IO) pada struktur base isolation.

Indonesia is prone to seismic disasters due to its location on the Pacific Ring of Fire and top of tectonic plates, making it susceptible to earthquakes that can cause damage to buildings and infrastructures. Along with advancements in construction technology, various technologies have been developed to reduce the influence of earthquake loads on buildings, one of them is the base isolation system. This research aims to compare the performance of structures between conventional (fixed base) buildings and buildings with base isolation, varying the effective damping of isolators at 2%, 5%, 10%, 15%, 20%, 25%, and 30%. Seismic analysis procedures adhere to SNI 1726:2019 using static equivalent and dynamic response spectrum methods. Structural performance evaluation follows ATC-40 guidelines utilizing static non-linear pushover analysis. The research results indicate seismic responses such as base shear forces, floor displacements, inter-story drifts, and internal forces in structural elements showing a negative trend (decrease) occurring non-linearly with increasing values of isolator’s effective damping. The structural performance evaluation reveals that the use of base isolators can enhance the structural performance level. structures with Damage Control (DC) level, the performance improves to Immediate Occupancy (IO) on base isolation structure.