서소문고가 붕괴 사고. 화장판이 거더 열화 촉진했나? (ft.토목구조기술사)

Did the decorative panels accelerate girder deterioration in the Seosomun Overpass collapse? (ft. Civil Structural Engineer) The most critical factor in the collapse of the Seosomun Overpass during its demolition was that the girders had lost their capacity to the point where they could no longer support their own weight. Looking back in time using Street View, I discovered that decorative panels had been attached to the bridge in 2008. These panels are difficult to inspect or diagnose, and if water seeps through them, they can accelerate structural deterioration. It seems they do not understand what is more important: aesthetics or safety. By 2008, it had already been 42 years since the bridge was completed. To think they attached decorative panels to a bridge that would not have been sufficiently reinforced. Related Video    • 구조엔지니어는 화장하는 걸 싫어해.   [00:04] Overview of the collapse accident during the demolition of the Seosomun Overpass and introduction to the video [00:51] Correction of errors in the Seoul Metropolitan Government's announcement (Girder No. 1, not Girder No. 16, collapsed) [02:32] Cause of collapse: The aging girder failed to withstand its own weight during the cutting process and broke [03:43] Signs of structural defects observed through past external steel cable reinforcement cases in other spans (S6) [05:42] The problem where the installation of 'cosmetic panels' for landscape improvement concealed internal corrosion and accelerated deterioration [08:36] The fact that PC steel cable fracture in the collapsed section (S9) was already discovered during the 2019 precision safety inspection [11:40] The core of the accident: Failure to recognize that the girder was so weak that it could not even withstand its own weight Construction in progress [13:23] Pointing out the construction discrepancy where the girder was cut as a whole, unlike the design plan which called for the slab to be removed in advance. [16:45] Circumstances indicating that external girder reinforcement was recommended during the 2019 safety inspection but was omitted on the grounds that it was scheduled for demolition. [18:42] Analysis that the 'level difference' phenomenon that occurred in the early morning was not a simple level difference but a girder 'failure' phenomenon, a precursor to collapse. [21:06] Proposal for effective emergency response measures, such as deploying additional cranes or forced drop, upon confirming signs of failure. [24:21] Pointing out the limitations of the multi-level reporting system and emphasizing the need for a 'pre-action, post-approval' system in urgent on-site situations. [25:38] Condolences for those who lost their lives in the accident and the conclusion of the video. #Bridge #CivilEngineering #StructuralEngineer #SeosomunOverpass #ReinforcedConcrete #PSC #PrestressedConcrete #ConstructionEngineer #CivilEngineer #ProfessionalEngineer #Demolition #Accident