ĐÀ NẴNG — No cracks have been found during expansion work on the Hải Vân Tunnel No 2 after a series of dynamite detonations were permitted between March and June, the project investor said yesterday.

In a written response to Việt Nam News, Đỗ Văn Nam, Director of the Đèo Cả Investment Joint Stock Company, the project’s main investor, emphasized that the construction had been done safely.

He said the Hải Vân Tunnel No 1, connecting Đà Nẵng City and Thừa Thiên-Huế Province, had been closed for 30 minutes every day starting from July 11 with approval from the Ministry of Transport.

The closure aims to facilitate expansion of Hải Vân Tunnel No 2 (parallel to the Hải Vân No 1).

Nam dismissed reports that some cracks were found on the southern section of Hải Vân Tunnel No 2.

He said the company started expanding a 420m section on the north side of the Hải Vân tunnel No 2 in late 2016, and no cracks or landslides were recorded since.

Nam said cracks were only found on surface of mortar layer of the Hải Vân Tunnel No 1 between 2005-2015 due to shrinking concrete.

He said the cracks had appeared on the wall mortar of Hải Vân Tunnel No 1 soon after it was completed in 2005, and these cracks did not affect the tunnel’s structure or operation.

During the last inspection in 2015, his company had co-operated with German consultancy firm Alpin Technik to examine all cracks on the arch of the Hải Vân Tunnel No 1 for carrying out repairs.

He said 25 per cent of total cracks have been identified for early repair work.

As scheduled, the Hải Vân Tunnel No 1 will be closed from 1.15pm to 1.45pm every day from July 11.

Vehicles are allowed to pass through Hải Vân Tunnel No 1 after stopping at two toll stations at the north and south ends.

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

The expansion of the Hải Vân Tunnel 2, which includes 5.85km-long entrance 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 go into operation in 2020.

According to Đèo Cả, nearly 2.8 million vehicle trips were made through the Hải Vân Tunnel 1 in 2016.

A report says there were 53 accidents and 41 vehicle fires between 2005 and 2014 in the Hải Vân Tunnel No 1. Eleven vehicles overturned inside the tunnel during this period. — VNS