"Apartment with Missing Rebar... Construction Company and Designer Cite Lack of Experience with 'Muryangpan Structure' as Cause"

Professor Hong Geon-ho of Hoseo University MBC Radio Interview
"Seems to Lack Expertise in Specialized Construction Methods"

Professor Hong Geon-ho of the Department of Architectural and Civil Engineering at Hoseo University pointed out the lack of expertise among construction site supervision companies as a cause related to the 'rebar omission' apartment incident.

Professor Hong, who served as the chair of the accident investigation committee for the collapse of the underground parking lot at a newly built apartment in Geomdan, Incheon, appeared on MBC Radio's "Kim Jong-bae's Focus" on the 2nd and said, "By law in our country, design and supervision are supposed to be carried out by architects," adding, "These professionals understand the overall design well, but their understanding of structural aspects can be somewhat lacking."

He continued, "Many do not understand how rebar should be arranged at joints," and said, "They probably know about routine procedures, but when it comes to specialized construction methods, their professional knowledge is somewhat insufficient, which I believe leads to such problems."

[Image source=Yonhap News]

Earlier, according to the Ministry of Land, Infrastructure and Transport's 'LH Flat Slab Structure Investigation Results,' among 91 complexes selected and constructed using flat slab systems since 2017, 15 complexes were found to have insufficient column reinforcement rebar, sparking controversy over poor construction quality.

Regarding the flat slab structure, Professor Hong explained, "A flat slab is a slab directly supported by columns without beams," and added, "To explain simply, imagine placing a pen and then putting a sheet of paper on top of it." He continued, "If you press down on the paper, it will puncture; this is commonly called punching shear. But if you imagine placing a book instead of a thin sheet of paper on the pen, it won't puncture."

He explained, "When there are beams or thick members like a book placed on top, punching shear does not occur, but since only a thin slab is present, punching shear happens."

Professor Hong said that shear reinforcement is necessary to prevent punching shear, but in the case of the underground parking lot collapse accident at the apartment construction site in Geomdan New Town, Incheon, shear reinforcement was not installed. He said, "If you think of the area where the pen touches as being covered with Scotch tape, it won't puncture," adding, "Reinforcing that part like Scotch tape is shear reinforcement, and because the shear reinforcement was missing, it could not resist punching shear."

Professor Hong stated, "The flat slab system is widely used not only in our country but also globally, and it has been verified as a construction method," and added, "After the collapse of the Sampoong Department Store, flat slab structures were used less in Korea, but recently their use has resumed."

He said, "Therefore, the lack of experience with flat slab structures among construction companies and designers was likely one of the causes," and added, "Furthermore, due to the lack of experience and knowledge about how rebar should be arranged at joints in such systems, I believe there was insufficient understanding."

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