Thu Thiem Tunnel is undergoing maintenance just after nine months of operation
Re-occurring cracks
Luong Minh Phuc, head of tunnel operator HCM City Urban Transport Development Management Board, said inspection will be carried out immediately.
Thu Thiem tunnel is the first of its kind in Vietnam, consists of four 1.5km long sections with a six-lane road.
In 2008, the four pre-built sections of the tunnel developed a series of 2-3 metres long cracks on the ceiling and walls. But these were fixed and passed inspection prior to the next stage in 2009.
When the tunnel was first put under water in 2010, the cracks appeared again at over 109 locations. The independent consultant, Oriental Consultants Company, said it was still within acceptable tolerance levels.
From then on, people were restricted from entering the unfinished tunnel. Although the repaired cracks are still visible but there were no reports of leaks.
Thu Thiem Tunnel was approved for operation in November 2011 and the contractors and consultants assured people of its safety.
However just after nine months of operation, the local Department of Transport said it would start periodical maintenance from July 21, with the cracks detected during routine maintenance.
Long cracks in the tunnel