Source: Taipei Times
The Yun Men Tsui Ti (雲門翠堤) commercial and residential complex, the building most seriously damaged in Tuesday’s magnitude 6.0 Hualien earthquake, is now the focus of an investigation to determine if human error was behind the partial collapse of four structures in downtown Hualien.
Hualien District Prosecutors’ Office head prosecutor Wang Yi-jen (王怡仁) said his office has retrieved the building construction licenses, building use permits and applications for alterations for all four of the buildings that suffered serious damage in the earthquake.
The buildings are the Yun Men Tsui Ti building, the Marshal Hotel (統帥飯店) and two apartment buildings.
The Yun Men Tsui Ti building is the focus of the investigation, because of the number of deaths — nine out of the 12 confirmed — attributed to its partial collapse, Wang said.
Civil engineers have said that the method used to connect the building’s steel bars likely contributed to the serious casualties reported at the site.
Architecture experts have also raised questions over the building’s receding facade and the ground-floor arcade, which was taller than it should have been, as it was used for stores.
According to construction regulations, the steel bars used in constructing the building should have been 1.3 times their actual lengths so they could be layered upon one another to enhance the building’s structural integrity, but they were not assembled in this manner, Tainan Structural Engineer Association director-general Huang Chia-jui (黃嘉瑞) and association member Wang Wu-lung (王武龍) said.
“As a result, the columns snapped like ropes,” Huang said, while Wang added that the way the steel bars snapped appeared “suspicious.”
By itself, each connection point between steel bars is weak, so the legal construction method is to make several connections converge, thereby enhancing the sturdiness of beams and columns, and Yun Men Tsui Ti had “clearly fallen short” in this regard, Huang said.
Based on a preliminary review of the building, the steel bars were not layered, which highlights problems in its safety, Executive Yuan Public Construction Commission Chairman Wu Tze-cheng (吳澤成) said.
However, the disproportionately heavy upper levels of the building likely caused the columns to give out, he said.
Yun Men Tsui Ti, like all other residential buildings in its proximity, sits on the Milun fault, but was the only one that collapsed during the earthquake, which raised questions over its construction quality, National Taiwan University geology professor Chen Wen-shan (陳文山) said.
The building collapsed in a roughly north-to-south direction, but it was the steel bars facing the north that were broken and exposed, indicating that that the building’s construction was likely flawed, New Taipei City Professional Civil Engineers Association chairman James Yu (余烈) said.