Hyundai Engineering, the construction company related to the collapse of a bridge in Anseong, Gyeonggi Province, which resulted in 10 fatalities, has explained the status of the accident and is working on measures to prevent a recurrence. The construction method used at the site is a common one frequently employed elsewhere, yet the sight of the entire bridge pier sinking helplessly shocked many experts. Some have raised the possibility that safety standards may not have been adhered to, noting that "it may have been supported solely by rebar without any bracing." Hyundai Engineering has not provided any response regarding this issue.
◆Experts say, "There are established construction guidelines, so the accident is an extremely unusual situation."
The collapse occurred at around 9:49 a.m. on the 25th at the construction site of the Seoul-Sejong Expressway in Sanpyeong-ri, Seowun-myeon, Anseong, Gyeonggi Province. A girder, a type of beam laid beneath the bridge deck structure, suddenly collapsed. The accident resulted in 4 deaths and 6 injuries, totaling 10 casualties.
It is reported that the subcontractor Jangheon Industrial was responsible for the installation of the girder, while Gangsan Development was in charge of placing the slab on top of the girder. The accident occurred during the process of using a special installation device known as a "launcher" (equipment for lifting and installing girders) to position the girder on the pier and then withdrawing the launcher, at which point the girder suddenly collapsed.
Experts diagnosed that the unusual accident involving a commonly used construction method may indicate inadequate safety measures. The construction method used at the site is known as the DR girder method.
This method simplifies on-site processes by pre-fabricating the bottom slabs and cross beams at the factory. Compared to standard girders, it offers flexibility in height adjustment, making it advantageous for bridge construction in rivers to secure cross-sectional flow areas (the area of passage through which streams or rivers traverse roads or bridges). Additionally, with factory production, it ensures consistent quality and allows for rapid construction, providing good performance in preventing floor slab cracks.
Choi Myung-ki, a professor at the Korea Industrial Site Professor Group, said, "The launcher structural component may have deviated from the center of the girder, causing the lower girder to tilt and become eccentric, which could have led to the accident," adding, "In the DR girder method, girders occasionally fall, and to prevent this, support structures such as bracing, safety ropes, and rebar should be in place. This accident appears to have occurred in an unstable state supported only by rebar."
He also noted, "Another possible speculation is that the launcher used at the site was a box-type launcher, which differs from the standard launcher. If the girder was unstable, this box-type launcher has the characteristic of easily tilting on the girder," explaining, "Using this box-type launcher could be a cause of the accident."
Park Ki-beom, a professor in the Department of Architectural Civil Engineering at Kyungil University, stated, "The DR girder method has been implemented in numerous cases, and the construction guidelines and sequences are somewhat established," and speculated, "When viewing the collapse video, it seems that there may have been inadequate adherence to safety protocols regarding securing structures and the criteria to be followed during launcher operations."
He continued, "In the video, the launcher moves on top of the girder and suddenly tilts sharply. It is possible that it did not move according to the set safety protocols regarding securing structures or when moving the launcher near surrounding facilities."
◆Hyundai Engineering, "We do not yet know the cause of the accident."
Hyundai Engineering maintains that it does not yet know the cause of the accident. Joo Woo-jeong, CEO of Hyundai Engineering, stated during a media briefing at the company's headquarters in Gaedong, Jung-gu, Seoul, on the 28th, that "the cause of the accident must be transparently revealed," while also noting, "We will cooperate transparently with the relevant authorities conducting the investigation and await the results." He emphasized that the investigation is ongoing and that the cause of the accident is yet unknown.
A Hyundai Engineering official also stated, "We hold a safety meeting every morning before work, check all safety equipment on site, and conduct risk assessments before beginning operations," and added, "Helmets, belts, safety rings, girder anti-tipping facilities, and fall prevention nets were all perfectly installed." When asked about the cause of the accident, he responded, "We cannot comment on the ongoing investigation at this time."
Meanwhile, on the same day, the Ministry of Land, Infrastructure and Transport established a construction accident investigation committee to determine the cause of the accident. At the same time, police conducted a search and seizure of Hyundai Engineering's headquarters as part of their investigation.