Technical issues on forensic assessment of post-earthquake building damage—Case study of the Hajj Dormitory Building, Mamuju, Indonesia

Abstract

In the wake of frequent, strong earthquakes in Indonesia, detailed and comprehensive forensic assessments of post-earthquake building damage are necessary. On January 14, 2021, a destructive Mw 6.2 earthquake occurred in Mamuju–Majene, West Sulawesi, Indonesia. Over a hundred houses and facilities were heavily damaged, and there were even fatalities and injured people. Therefore, forensic work is required to assess the conditions and performances of existing buildings to ensure their safety. However, determining a building’s seismic capacity and safety after an earthquake is a challenge. It is substantially challenging to accomplish it solely through visual inspections, which must be done rapidly and during an emergency. This paper reports a complete assessment of the Hajj Dormitory building. An extensive forensic method including visual and detailed inspections was planned and performed. Detailed inspections comprised verticality, ultrasonic pulse velocity test, rebound hammer test, crack measurement, rebar scan/cover meter test, core drill, and geoelectric and cone penetration tests. Results showed that the Hajj Dormitory building superstructure was still safe and reliable; however, mandatory retrofitting was required in several parts of the column and beam. Further, technical issues associated with post-earthquake forensic methods of observed damage and their utility on the safety and reliability of an inspected building are presented, and recommendations are made based on extensive in situ work. Moreover, correlations and recommendations for each forensic method are presented, along with detailed rules of damage assessment.