BANGKOK — A construction expert provided information to the special investigation team and expressed concerns about the collapsed State Audit Office building. He pointed out contract revision number 4 of 9 total changes that included changes to the elevator shaft and executive corridor.
Mr. Wira Ruangsri, manager of 3117 BIM Management, shared details with the Department of Special Investigation (DSI) on May 5 about the structural aspects of the State Audit Office (SAO) building, which collapsed on March 28 after an earthquake.
His statement clarified the line of inquiry into the only building in Bangkok that collapsed in the quake.
Wira, a specialist in construction supervision, design and Building Information Modeling (BIM), offered insights into three key areas:
- The reasons for the nine contract revisions.
- Technical concerns regarding the structure of the building.
- The provenance and accountability of the designers, engineers and project managers.
The Controversial Redesign
Of the nine revisions, only the fourth was classified as structurally significant. The others were mostly numerical adjustments, budget changes or extensions to the timetable with no major impact on the design.
The fourth revision included a redesign of the elevator core, the shear walls and the associated structural elements. It also included adjustments to the core walls of Building A from floors B1 to 3, where the beams were moved to accommodate the supply systems, resulting in the elevator shaft being modified all the way to the roof.
According to the Building Control Act of 1979, corridors must be at least 1.5 meters wide. Two widths were created during the redesign: 1.5 meters (adjusted to 1.6 to allow tiles to be laid) and 2.10 meters. The question arises: why extend to 2.10 meters if this is not required by law? The answer could lie in the intention to lay granite tiles in the elevator area to give it a more luxurious look.
Whether the Elevator Brand is Fixed?
In addition, concerns were raised about the specification constraint in the design of the elevator. Although it would be technically possible to reduce the shaft wall by 5 cm on each side without compromising functionality, the original design specified the elevator brand, model and shaft size in the Terms of Reference (TOR).
This raises the suspicion that the specifications were deliberately fixed. Further investigation is required to determine whether the design really could not be changed or whether other motives were at play.
Regarding the approval of documents, Wira explained that architectural revisions must be signed off by a licensed architect, while structural revisions require the endorsement of a senior engineer. SAO’s own regulations state that any design certified by the project designers must also be validated by a supervising engineer from the PKW joint venture before it is passed on to the contractors.
Error in the Structure of the Tower
As far as the statistics were concerned, Wira commented on the question of the foundation at the rear of the SAO building. There were two foundation designs: one original and one modified. Although he was not obliged to do so, the contractor improved the foundation.
However, there are still inconsistencies in the reinforcement: all the columns in the 3-story parking area were reinforced, while the 30-story tower had smaller steel bars and other personnel. This is legal, as they are separate buildings, but it points to an error in the structure of the tower. Miscalculations may have caused the tower to tilt backwards during the collapse, which is related to the weakened elevator shaft.
Wira noted, “At the site, five columns from the 19th floor can be seen to have fallen in a line into the elevator pit, showing that the building slid backwards, breaking these columns and causing a direct collapse through the hollow elevator shaft.”
30 Signatures Were Forged
Meanwhile, interviews with 38 engineers listed in the SAO’s construction supervision documents revealed that 30 signatures were forged, and only 8 engineers admitted that the permits were genuine.
The DSI Director General Pol. Lt. Col. Yutthana Praedam explained the focus of the investigation: Testimonies of engineers whose names and signatures were forged, evidence collected at the site of the collapse, and the investigation into possible violations of the 1999 Act on Offenses related to the submission of tenders to state authorities, particularly in relation to project tendering and supervision by the PKW Joint Venture.
The PM Really Needs Answers
Earlier, Prime Minister Paetongtarn Shinawatra said that she is waiting for the investigation results to find out the true information about how only the Office of the Auditor General building collapsed. The Department of Public Works has requested 90 days to investigate and simulate the incident.
She feels this is too long because if Thailand cannot provide answers about this matter and doesn’t know where the mistake occurred, it will be considered a major issue, especially after many people died due to the entire building collapsing.
“As a human being, I cannot accept this situation. And I will not accept if there are no answers. Therefore, I am closely following this matter and have already instructed the DSI that if there were mistakes in the approval process, legal action must be taken. Whether the design was correct or not – if it was wrong, then it was wrong. We haven’t even gotten to discussing the building collapse yet,” the Prime Minister said.
Turned Over All Building Floors
Meanwhile, the Command Center for the State Audit Office building collapse incident in Chatuchak District, Bangkok, allowed media to enter a building near the collapsed ruins to survey and take photographs, as well as to update information about the search and debris removal on May 6. After completely opening up the concrete basement floor areas, both around and inside the building, covering a total of 40 meters by 40 meters.
Suriyachai Ravivan, Director of the Office of Disaster Prevention and Mitigation of Bangkok Metropolitan Administration, stated that the search for missing persons in the building has not found additional bodies, even though they have turned over all building floors. Therefore, they must wait for the identification of more than 200 human remains that the search team has sent to the Institute of Forensic Medicine at Police General Hospital for DNA testing to determine how many individuals they belong to.
Currently, according to investigation officers’ information, there are a total of 109 casualties: 87 deaths, 13 missing persons, and 9 injured.
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