Seongsan Bridge Deck Cracks in Seoul "No Safety or Durability Issues"... Joint Investigation Team Announcement

Six Independent External Experts 'Seongsan Bridge Safety Verification Joint Investigation Team' Conduct Detailed Inspection
Actual Crack Width Below 0.2mm Concludes No Safety Issues... Repairs to Be Completed by November to Enhance Durability

[Image source=Yonhap News]

[Asia Economy Reporter Lim Cheol-young] Seoul City announced that it has confirmed no safety issues following an investigation into floor slab cracks discovered during performance improvement work on the aging Seongsan Bridge.

On the 24th, under the direction of Mayor Oh Se-hoon, the 'Seongsan Bridge Safety Verification Joint Investigation Team,' formed without Seoul City's involvement, announced that the floor slab cracks on Seongsan Bridge occurred during temporary placement of floor slabs to secure traffic lanes while a large crane was conducting installation work. They confirmed that safety was not compromised after testing with the maximum allowable load for road traffic.

The joint investigation team, composed entirely of external experts, concluded from detailed inspections that the actual crack width was less than 0.2 mm, posing no issues to safety or durability. To ensure impartial results, Seoul City operated the 'Seongsan Bridge Safety Verification Joint Investigation Team,' consisting of six external experts in facility safety, roads, and construction, from April to June this year (for two months).

The joint investigation team analyzed design and construction data, selected the sections at the south and north ends where cracks were most severe, installed work platforms for close-up inspections, and conducted detailed investigations into the condition and distribution of the cracks. They installed precision measuring instruments capable of measuring 0.001 mm at the lower part of the precast floor slab cracks and injected colored epoxy into the cracks to collect samples for precise crack width measurement.

Regarding why the visible surface cracks appeared larger than the actual cracks, it was confirmed that the crack areas were damaged during the removal of existing coatings after floor slab replacement, which caused the surface crack width to increase. The removal process used a 'blasting method' where small steel balls were sprayed with high-pressure compressed air, which damaged the surfaces of the fine cracks.

The joint investigation team also conducted load tests by passing two dump trucks, each with a total weight of 40 tons?the maximum allowable load for road traffic?to confirm that safety was not compromised even when trucks carrying the maximum traffic load passed over the bridge. Load testing is a method of applying force or weight to structures such as bridges to assess their endurance.

Although Seoul City confirmed no safety issues from the detailed investigation, it plans to begin comprehensive repairs on the cracked areas to secure the long-term usability and durability of Seongsan Bridge, aiming to complete the work by November. Kim Sang-hyo, Honorary Professor at Yonsei University and chair of the joint investigation team, explained, “This safety verification of Seongsan Bridge is an objective result thoroughly investigated from the perspective of the citizens who use it,” adding, “Citizens can use the bridge with confidence.”

This content was produced with the assistance of AI translation services.