ĐÀ NẴNG — The Directorate for Roads of Việt Nam has asked the Đèo Cả Investment Joint Stock Company, main investor of Hải Vân Tunnel, to examine cracks on the walls of Hải Vân Tunnel No 1.

The cracks were discovered on the southern side of the tunnel, which connects central Đà Nẵng City with central Thừa Thiên-Huế Province.

Leaders of the Directorate for Roads of Việt Nam plan to visit Hải Vân Tunnel No 1 today to assess the cracks.

The Đèo Cả Company has affirmed that the cracks have not affected the tunnel’s structure or traffic, even as expansion work is underway on Hải Vân Tunnel No 2, which runs parallel to Tunnel No 1.

Lê Quỳnh Mai, deputy general director of the company, told Việt Nam News on Tuesday that the cracks did not impact the overall structure of the tunnel and that the cracks were actually the previously-fixed ones.

Eight serious cracks were found on the surface of the mortar in Tunnel No 1 between January and May 2016 when management of the tunnel and the single-lane rescue tunnel (now Hải Vân Tunnel No 2) was transferred by the Ministry of Transport.

The company, in co-operation with Japanese consultants Nippon Koei and German firm Alpin Technik, repaired the cracks, which was approved and inspected by the transport ministry in late 2016.

Cracks on the wall of Hải Vân Tunnel No 1. No more new cracks were recorded between December 2016 and September 2017 when expansion work was developing. — VNS Photo Đình Thức

Mai said the cracks were covered with a coat of 12-year-old epoxy paint, which peeled off by 1-3cm, making the cracks look wider.

Mai dismissed rumours that the cracks resulted from a series of dynamite detonations during expansion work.

He said the single-lane Hải Vân Tunnel No 2, built as a rescue tunnel for Hải Vân Tunnel No. 1 in 2005, was expanded to a two-lane 6.29km long tunnel to accommodate increasing traffic on trans-Việt Nam National Highway No 1.

He said no new cracks were visible on Hải Vân Tunnel No 1 during expansion work on Hải Vân Tunnel No 2 after a series of dynamite detonations were permitted over 12 months.

Vehicles are still travelling through Hải Vân Tunnel No 1 while expansion work is taking place on Hải Vân Tunnel No 2.

The company again confirmed that no new cracks or landslides were recorded in Hải Vân Tunnel No 1 since the old cracks were repaired last December.

The expansion of Hải Vân Tunnel 2, which includes 5.85km-long roads on either side, infrastructure and rescue lanes between the two tunnels, is set to cost VNĐ7.3 trillion (US$323 million). It is scheduled to be put in operation in 2020.

According to Đèo Cả Co., nearly 2.8 million vehicles travelled through Hải Vân Tunnel 1 in 2016. — VNS