The scene of the Gwangju Representative Library collapse. The Ministry of Land, Infrastructure and Transport announced that its construction accident investigation committee found the collapse was caused by systemic failures throughout the truss welding process. [Ministry of Land, Infrastructure and Transport]
The scene of the Gwangju Representative Library collapse. The Ministry of Land, Infrastructure and Transport announced that its construction accident investigation committee found the collapse was caused by systemic failures throughout the truss welding process. [Ministry of Land, Infrastructure and Transport]

Systemic failures throughout the truss welding process have been identified as the cause of the Gwangju Representative Library collapse in Seo-gu last December, which killed four people. Experts concluded the disaster was a man-made accident resulting from defective welding that deviated from design specifications, compounded by inadequate inspections.

The Ministry of Land, Infrastructure and Transport announced Thursday that its construction accident investigation committee had reached those findings regarding the Dec. 11 collapse at the library construction site in Seo-gu, Gwangju. The structure gave way when weld joints on a truss failed during concrete pouring on the roof level, killing four workers.

The committee found that the installed weld joints reached only 22 to 31 percent of the design specification strength, and that the joints fractured under the increasing weight of the building during construction, triggering the collapse.

During the welding process, workers improperly inserted foreign materials — including rebar — into weld zones, constituting serious defective construction that the committee identified as the most direct cause of the collapse. Opportunities to prevent the accident were also lost: construction detail drawings guiding proper welding methods were neither adequately prepared nor reviewed, and post-construction weld inspections were insufficient. Improper site management, including the use of welders whose qualifications had not been verified on site, also contributed.

The committee said both the contractor and the construction project manager bear responsibility for the casualties resulting from the defective work. The contractor failed to prepare construction detail drawings before breaking ground and did not properly verify the qualifications of the welders it deployed. It also failed to prevent the unauthorized insertion of foreign materials into the weld zones.

The supervising engineer neglected to review the construction detail drawings and showed broad failures in oversight, including inadequate verification of welder qualifications and insufficient weld inspections.

To prevent similar accidents, the committee proposed measures to strengthen welding quality management and improve the competency of construction participants.

The recommendations include revising standard specifications to set more detailed welding quality inspection standards and procedures, tightening management of high-difficulty welding work, clearly defining construction project managers' obligations to verify welding and post-construction inspection plans under the guidelines governing construction project management, clarifying on-site welder qualification verification requirements, and raising the skill level of field workers through basic training and various incentives.

Choe Byeong-jeong, chair of the investigation committee, said the committee "worked with numerous experts across relevant fields to conduct an objective and scientific accident investigation," adding that he hoped the identified causes and prevention measures would help ensure no similar accidents occur in the future.

Separately from the cause investigation, the ministry's Iksan Regional Office of Construction Management conducted a special inspection of the Gwangju Representative Library construction site in June, together with the Korea Infrastructure Safety Corporation and private experts, to verify the deficiencies uncovered during the investigation and check compliance with relevant laws. The inspection found violations including failure to implement safety management plans, inadequate management of quality control engineers, and illegal subcontracting to unregistered parties. It also reconfirmed poor welding conditions, including rebar inserted into weld zones and incomplete construction that deviated from the drawings.

The Iksan office plans to swiftly proceed with criminal referrals for the legal violations and pursue administrative sanctions including penalty points and fines in parallel.

In addition, the ministry will share the committee's findings with related ministries and local governments to disseminate lessons from the accident and push for stronger on-site safety management to prevent recurrence. It also plans to pursue business suspension orders against the contractor and construction project manager for defective construction and supervision, and will share all investigation findings with police, the Ministry of Employment and Labor and other investigative agencies to support strict criminal action on charges including occupational negligence causing death or injury and violations of industrial safety laws.

The Gwangju Representative Library collapse occurred on Dec. 11 last year when a steel structure at a construction site in Chipyeong-dong, Seo-gu, Gwangju, gave way. Four people — construction workers and an employee of a government-supplied materials vendor — were buried and died at the scene. Earlier, the National Disaster and Safety Research Institute under the Ministry of Interior and Safety had, after more than five months of investigation, identified basic construction defects including faulty connection welding and the use of unqualified welders as causes of the accident. Following the collapse, the site manager of the contractor, the head of the supervision team, and the representative and site manager of the subcontractor responsible for the steel frame work were all taken into detention.


smh@heraldcorp.com