Jeongneungcheon Overpass, with 100,000 vehicles passing per day, is at a ‘red light’… “Repeated damage to steel cables” (comprehensive)

It was discovered that the external tension member (tendon) of the Jeongneungcheon Overpass bridge, which carries more than 100,000 vehicles a day, has repeatedly broken.

It was also pointed out that replacement was being delayed even though corrosion and damage to some tendons were confirmed.

On the 19th, Rep. Hwang Hee of the Democratic Party of Korea, a member of the Land, Infrastructure and Transport Committee of the National Assembly, announced this after analyzing data submitted by the Seoul Metropolitan Government and the National Land Safety Management Agency.

Tendons are steel cables that strongly pull the concrete from the inside to support the weight of the vehicle. If the tendon, which is the core supporting bridge, breaks, it can lead to a serious accident.

In 2016, the tendon of the Jeongneungcheon Overpass broke (ruptured) and the city of Seoul restricted traffic for about a month. The city replaced 32 damaged cables and continued to take measures such as blocking water leaks and conducting quarterly inspections.

However, tendon rupture occurred again in 2024 and 2026.

In particular, the city conducted a detailed safety diagnosis from May 2023 to March of the following year and a detailed safety inspection from February 2025 to March 2026, and gave it a grade B, which is a good level, saying there were no major defects. However, it was discovered that tendon rupture occurred shortly after.

Representative Hwang pointed out that even though the break occurred again, the city did not implement safety measures such as traffic control, installation of hazard signs, and notification to residents.

In addition, the city conducted a comprehensive survey of tendons from September 2024 to August of the following year and discovered 25 tendons with confirmed corrosion and damage within the Jeongneungcheon Viaduct.

According to government standards, corrosion accompanied by damage to cables and loss of cross-section is considered a major structural safety defect and a grade D, but the city attempted to reduce the severity by separately classifying it as grade C3, which is its own standard, Rep. Hwang argued.

Replacement is also slow. It is said that 25 damaged cables identified in the comprehensive investigation have not yet been replaced.

Rep. Hwang pointed out, “It is a total failure of the Seoul Metropolitan Government’s safety management system to continue to judge ‘good’ even after the tendon broke three times and to leave 25 seriously damaged cables unattended for two years,” adding, “It is a clear administrative maladministration caused by Seoul Mayor Oh Se-hoon’s lack of safety awareness and delay in investing the safety budget.”

He added, "To prevent the tragedy of the collapse of Seosomun High School from recurring, the entire Jeongneungcheon Viaduct tendon must be reevaluated in accordance with detailed national guidelines, and the results and specific replacement plans must be transparently disclosed to Seoul citizens."

The city explained that in the 2023 and 2025 inspections, it was not possible to inspect the concrete interior, and the entire facility, including tendons, was evaluated and a B grade was given.

During regular inspections that followed, the rupture was confirmed by visually observing that the externally exposed steel wire was sagging.

During a complete survey in 2024, corrosion and damage to tendons were discovered using a non-destructive method of drilling a fine hole in the bridge and examining the interior.

In addition to the tendon in question, the city plans to add 10 tendons near the area where the breakage was previously discovered, for a total of 35 tendons to be replaced by June of next year. The required budget was set at 7.2 billion won.

Additionally, city officials explained that the C3 grade indicates the degree of corrosion and that comparison with general safety grades is not appropriate.

Regarding the lack of separate control when fractures were discovered in 2024 and 2026, the city explained that it was the result of a service commissioned by the Korea Concrete Society.

In the service conducted in 2017 to establish standards for traffic control when fractures are discovered, it was concluded that it was okay to replace up to four tendon fractures without traffic control.