An integrated Approach of Rapid Visual Screening and Fault Tree Analysis in Assessing Reliability of Low-Rise Building in Active Seismic Zones

Abstract

This study aims to assess the seismic reliability of low-rise residential buildings in Surabaya’s western districts, which lie along the active Kendeng Fault. By integrating Rapid Visual Screening (RVS) and Fault Tree Analysis (FTA), the research evaluates both observable vulnerabilities and underlying failure mechanisms within 30 informally constructed homes. The RVS results indicate that 76.7% of buildings require further evaluation and 23.3% are classified as unsafe, with none meeting the minimum safe criteria. Major risk factors identified include shallow foundations, lack of reinforcement, unanchored heavy roofs, and plan irregularities. The application of FTA revealed that structural failure often results from the interaction of multiple weaknesses rather than a single cause. This integrated RVS-FTA approach not only enhances vulnerability diagnostics but also informs prioritized retrofitting strategies. The findings support the need for holistic mitigation efforts involving structural reinforcement, community education, and localized policy reform to reduce disaster risks in urban informal settlements.