Viaduct collapse: Cracks discovered at 11 locations of remaining structure, says LTA
Cracks were found at 11 locations on the corbels holding up the viaduct. Image: LTA
SINGAPORE – A week after one worker was killed following the collapse of a section of a flyover viaduct, cracks have been discovered at 11 locations on the remaining structure being constructed at Upper Changi Road East.
The cracks were discovered at the corbel area, and investigations are underway to determine their “nature and cause”, said the Land Transport Authority (LTA) on Friday (July 21).
Corbels are stone structures on vertical columns that help to prop up horizontal beams that roads are laid on.
The LTA said the structural integrity of the remainder of the viaduct had been inspected and assessed to be safe, with additional support erected to prop up the beams adjacent to the collapsed section.
“As a further precautionary measure, the propping was extended to all the remaining spans where cracks were discovered at the corbel area at 11 locations,” it added.
The July 14 incident, which killed one worker and injured 10 others, was one of the worst construction accidents here since the 2004 Nicoll Highway collapse.
The accident happened while the workers were atop an elevated structure, carrying out decking works for the uncompleted flyover.
Investigations showed that the corbels underneath them suddenly gave way, sending the workers crashing down. A multi-agency team is trying to figure out the “root cause” of the collapse, said the LTA.
Associate Professor Gary Ong, from the civil and environmental engineering department of the National University of Singapore, said that cracks mean that the sections where they appear are overstretched – possibly due to overloading, design issues or material deficiency issues.
“This means that something needs to be done. I didn’t look at the cracks myself, but if they came about at some critical area, it can be dangerous,” he added.
Six of the 10 workers who were sent to Changi General Hospital remained warded on Friday. The LTA said it will continue to provide the necessary support to the affected workers and their families.
