No cracks have been found during expansion work on the Hai Van Tunnel No 2 after a series of dynamite detonations were permitted between March and June, the project investor recently said.

The Hai Van Tunnel No 2 is being expanded to serve increasing traffic. VNS Photo

In a written response to Viet Nam News, Do Van Nam, Director of the Deo Ca Investment Joint Stock Company, the project’s main investor, emphasised that the construction had been done safely.

He said the Hai Van Tunnel No 1, connecting Da Nang and Thua Thien-Hue 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 the Hai Van Tunnel No 2 (parallel to the Hai Van No 1).

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

He said the company started expanding a 420m section on the north side of the Hai Van 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 Hai Van Tunnel No 1 between 2005 and 2015 due to shrinking concrete.

He said the cracks had appeared on the wall mortar of the Hai Van 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 Hai Van Tunnel No 1 for carrying out repairs.

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

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

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

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

The expansion of the Hai Van Tunnel 2, which includes 5.85km-long entrance roads on either side, infrastructure and rescue lanes between the 2 tunnels, is set to cost 7.3 trillion VND (US$323 million).  It is scheduled to go into operation in 2020.

According to Deo Ca, nearly 2.8 million vehicle trips were made through the Hai Van Tunnel 1 in 2016.

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

(Source: VNS)