Bangkok, March 30, 2025 – In the wake of the collapse of the under construction State Audit Office building in Bangkok’s Chatuchak district, some building experts have pointed to potential flaws in the quality of the steel reinforcements used in its construction. However, further testing is needed.
The 33-story structure, still under construction with a budget of 2.136 billion baht, crumbled on March 28 following a powerful 8.2 magnitude earthquake centered in Mandalay, Myanmar, as we have extensively reported over the weekend here at TPN Media.
The earthquake, which struck at 1:20 PM on March 28, sent shockwaves across Thailand, with its effects felt as far as Bangkok, over 1,100 kilometers from the epicenter. While most buildings in the capital withstood the tremors, the State audit building was the only high-rise reported to have collapsed entirely, resulting in loss of life and ongoing rescue efforts. As of the latest updates, 18 fatalities have been confirmed, with 33 injured and 78 people still unaccounted for across 11 affected sites in Bangkok.
Posts on social media and statements from alleged engineering professionals have highlighted a troubling hypothesis: The steel reinforcements, specifically identified as DB.32 SD.50 grade, may have been substandard. According to one expert cited in online discussions, laboratory tests on this type of steel have consistently shown a low yield strength, despite meeting minimum tensile strength requirements of over 5,000 kg/cm². Critically, the steel reportedly exhibits issues during bending tests, with tendencies to crack or split into layers, suggesting a major issue and problem for structures in seismic zones.
“This type of steel has a history of problems,” noted an anonymous civil engineering veteran online . “The low yield point combined with poor bending performance makes it a risky choice for tall buildings, especially in an area that could experience seismic activity. If this was indeed used in the collapsed building, it could explain why it failed so catastrophically while others stood firm.”
The State audit building, a flagship project overseen by a joint venture between Thai and Chinese companies, was approximately 30% complete at the time of collapse. The project, intended to serve as a modern headquarters for the State Audit Office, featured a 30-story office tower and a three-story training facility, boasting advanced audiovisual and IT systems.
Thailand’s Minister of Industry, Ekanat Prompan, has responded swiftly, dispatching a specialized team to collect samples of the steel reinforcements from the wreckage. Speaking to the press on March 29, he vowed to “deal decisively” with any evidence of substandard materials, emphasizing that the use of inferior steel in a government-funded project would be unacceptable. “We’re gathering evidence, including rebar and concrete fragments, to test at the Ministry’s Iron Institute. If we find quality issues, those responsible will face consequences,” he stated. Testing is ongoing as of press time.
The collapse has also reignited debate over Thailand’s seismic preparedness. While the country is not located on a major tectonic plate boundary, it is periodically affected by earthquakes originating from neighboring regions, such as Myanmar’s Sagiang Fault. The unprecedented scale of this event has prompted experts to call it a “wake-up call” for the construction industry. Dr. Siwat Phongpiachan, Director of the Disaster Prevention and Management Research Center, remarked in an interview with PPTV on March 28, “Natural disasters like this are unpredictable, but our buildings must be designed to withstand them. The collapse should force us to re-evaluate standards, especially for high-rises.”
As rescue operations continue, with teams using radar to locate survivors trapped in the rubble, the focus is shifting toward accountability. An investigative committee, chaired by a senior engineer from the Department of Public Works and Town & Country Planning, has been established to probe the collapse. Key questions include whether the steel’s deficiencies were a primary factor, if design flaws contributed, or if construction practices deviated from approved plans.
The Thai Prime Minister, as we reported here, has called for an investigation with initial answers as to why the building collapsed within a week, which is being led by the Minister of the Interior and Deputy Prime Minister Anutin Charnvirakul.
