An X-ray poster depicting a broken spine, part of a guerrilla campaign calling for a structural safety probe of Seongsu Bridge. [Lee Je-seok Advertising Lab]
An X-ray poster depicting a broken spine, part of a guerrilla campaign calling for a structural safety probe of Seongsu Bridge. [Lee Je-seok Advertising Lab]

A poster showing a broken human spine has appeared at the southern approach to Seoul's Seongsu Bridge, at the spot where a 9-centimeter step gap has formed and raised public concern.

Lee Je-seok, head of Lee Je-seok Advertising Lab, a public-interest advertising firm, said Wednesday he had launched a guerrilla campaign at the site of the visible step gap on the southern approach ramp of Seongsu Bridge to call for a thorough investigation of the ground beneath the road.

The advertisement placed X-ray images of a broken spine on both sides of the concrete retaining wall where the gap appeared, with the message: "You have to look inside to see it." The design conveys the danger of the gap in an immediately intuitive way.

Lee said the southern approach ramp is a filled-earth section reinforced with retaining walls, and that — roughly 30 years after the bridge's reopening — the internal drainage systems may have deteriorated and soil erosion may have occurred.

He particularly cited heavy rainfall, the soft ground around the Han River, and nearby construction — including the Great Train Express (GTX)-A line's under-river tunnel beneath the Han River and the underground rerouting of the East Seoul Expressway — as key risk factors.

Lee urged authorities to conduct a detailed investigation, including ground-penetrating radar (GPR) surveys and subsurface drilling, saying that simply patching the gap with asphalt makes it difficult to detect voids or soil loss beneath the road.

He also called for the results of any such investigation to be made fully transparent to the public.

After a stream of complaints from motorists using the stretch, the Seoul Metropolitan Government carried out an on-site inspection, repaired sections including guardrail joints, and decided to commission a full safety assessment in response to public concern.

A Seoul Metropolitan Government official said the stretch had been closely monitored and managed for more than a decade, and that there was no cause for concern about collapse or structural safety issues. "However, to put citizens' safety concerns to rest, we will immediately conduct a safety assessment to ensure there are no problems, and will manage the area thoroughly to prevent similar concerns from arising," the official said.


jshan@heraldcorp.com