The Seoul Metropolitan Government will remove asphalt concrete pavement and directly inspect ground conditions to determine the cause of a level gap found on the entry ramp at the southern end of Seongsu Bridge.
The city said on the 26th that it will conduct on-site testing on the southern ramp section of Seongsu Bridge on the 29th, with the participation of external experts in structural and soil engineering. The measure follows growing public concern after a level gap of about 9 centimeters was found on the southern ramp section leading from Olympic-daero toward Jamsil into Seongsu Bridge.
The test target is the southern ramp section leading into Seongsu Bridge from the Jamsil-bound direction of Olympic-daero near Dongho Bridge. For the on-site testing, the ramp will be fully closed from 9 p.m. on the 29th until 6 a.m. the next day, and one of the four adjacent lanes of Olympic-daero will also be partially closed.
The level gap occurred not on the bridge body itself but in a connecting retaining wall section built by piling up soil. The Seoul Metropolitan Government plans to remove the asphalt concrete pavement and directly inspect the structures and ground conditions beneath the pavement to confirm whether the retaining wall's ground has sufficient bearing capacity.
After the on-site testing, the section from the ramp entry to the bridge connection will be repaved to reduce the jolting that occurs when vehicles pass, improving driving stability and ride comfort. The city plans to comprehensively analyze the results of this on-site testing and the ongoing precise safety diagnosis to assess the condition of the facility, and to prepare repair and reinforcement measures if necessary.
The Seoul Metropolitan Government has been continuously inspecting the structure and ground conditions through joint inspections with external experts, ground-penetrating radar (GPR) surveys, and the installation of measurement gauges. In the joint inspection conducted since the 9th of this month, external experts said the level gap occurred at the boundary between the bridge structure and the retaining wall built from soil, and that it does not affect the safety of the bridge body. A GPR survey on the 10th of the lane where the gap occurred and two adjacent lanes also found no underground voids or abnormalities that could affect safety. In addition, the GPR survey of the lane where the gap occurred and two adjacent lanes found no underground voids or abnormalities that could affect safety.
"Inspection results so far have confirmed there is no problem with structural safety, but we will conduct on-site testing in parallel to ease public anxiety and do our best in facility management with safety as the top priority," said Choi Jin-seok, head of the Seoul Metropolitan Government's Disaster and Safety Management Office.
