STUDI PERBANDINGAN BIAYA-MANFAAT RETROFITTING STRUKTUR BANGUNAN EKSISTING BERDASARKAN TIER 1 ANALYSIS ASCE 41-17 - Hartman, Gilbert; Anondho, Basuki; Waty, Mega; Thedja, Julian (JMTS: Jurnal Mitra Teknik Sipil, 2025)
A significant proportion of existing buildings in Indonesia were constructed prior to the adoption of modern seismic design standards, resulting in a high level of vulnerability to earthquakes. This poses a serious threat to occupant safety and the continuity of building functionality during seismic events. This study aims to evaluate retrofitting strategies using the ASCE 41-17 approach to enhance the seismic resilience of existing structures. A total of eight buildings in the Jakarta area were analyzed using the Tier 1 checklist to identify structural vulnerabilities. Based on field inspections, retrofit methods such as the addition of structural elements, column jacketing, expansion joints, and detailed structural surveys were proposed. Cost estimates were prepared through a Bill of Quantities (BOQ) and evaluated using a Benefit-Cost Analysis approach. The results indicate that most retrofit methods yield benefit-cost ratios significantly greater than 1, suggesting that the benefits of improved seismic performance outweigh the associated costs. This study provides practical and effective retrofit recommendations, which can serve as a reference for policymakers, building owners, and civil engineering practitioners in planning structural strengthening of existing buildings in earthquake-prone areas. Abstrak Sebagian besar bangunan eksisting di Indonesia dibangun sebelum adopsi standar desain seismik yang mutakhir, sehingga memiliki tingkat kerentanan tinggi terhadap gempa bumi. Kondisi ini menjadi ancaman serius bagi keselamatan penghuni dan keberlanjutan fungsi bangunan saat bencana terjadi. Penelitian ini bertujuan mengevaluasi strategi retrofitting menggunakan pendekatan ASCE 41-17 untuk meningkatkan ketahanan seismik bangunan eksisting. Sebanyak 8 bangunan di wilayah Jakarta dianalisis menggunakan checklist Tier 1 untuk mengidentifikasi kerentanan struktural. Berdasarkan hasil inspeksi lapangan, ditentukan metode retrofit seperti penambahan elemen struktur, jacketing, sambungan dilatasi, dan survei detail struktur. Estimasi biaya disusun melalui Rencana Anggaran Biaya (RAB) dan dianalisis menggunakan pendekatan Analisis Biaya-Manfaat. Hasil menunjukkan sebagian besar metode retrofit memiliki nilai signifikan di atas 1, menandakan bahwa manfaat yang diperoleh dari peningkatan ketahanan terhadap gempa melebihi biaya yang diperlukan. Penelitian ini memberikan rekomendasi solusi retrofit yang layak dan efektif, serta dapat dijadikan acuan bagi pemangku kebijakan, pemilik bangunan, maupun praktisi teknik sipil dalam merencanakan penguatan struktur bangunan eksisting di wilayah rawan gempa.