Service tunnel added as escape passage during an emergency
Thirty-four tunnel projects, in progress across the country on National Highways (NHs), are designed with the highest level of safety, Minister of Road Transport and Highways Nitin Gadkari has assured the Rajya Sabha.
“All projects are designed with safety as a paramount consideration,” said the Minister, pointing out that 26 of these tunnels are in the Himalayan region.
These projects are implemented as per site-specific requirements, established codes, incorporating essential safety measures including those for emergencies such as escape tunnels, twin tubes with cross passages, separation wall with emergency openings, lay-byes, automatic fire detection and suppression systems etc.
As per IRC: SP:91-2019 (Guidelines for road tunnels) separate service tunnel, adjacent to the traffic tunnels could be considered at design stage considering various factors like land availability, traffic volume, length of tunnel and additional cost, he said.
“This additional tunnel provides access for maintenance without requiring tunnel closure. This service tunnel can be used as escape passage during an emergency.”
In the Silkyara bi-directional tunnel on Dharasu–Yumunotri highway (NH-134), a provision of separation wall has been provided at the centre of the carriageway along with egress openings at an average interval of 565 m for vehicular crossover and at an average interval of 300 m for pedestrian cross passage for escape purposes during the emergencies, he explained.
The trapped workers in a section of the collapsed Silkyara were given medical aid and found in good mental and physical health, he added in a written reply to the house.
As financial support, each worker has been paid a sum of Rs.2 lakh in addition to one month paid leave by the Executing Agency.
In addition to above, the Uttarakhand Government has also provided financial support to all trapped workers of Rs.1 lakh each.
The Rs.1,383.89 crore tunnel is designed to provide all weather connectivity to Yamunotri, one of the dham on Chardham Yatra, encouraging regional socio-economic development, trade and tourism within the country.
It will reduce the travel distance from Dharasu to Yamunotri by about 20 km and travel time by about an hour. The proposed tunnel will save number of trees that would have been required to be removed in the road improvement of 25.600 km, had the original alignment been followed.
The 4.531 km two lane Bi-Directional tunnel (along with 328m approach road) has an escape passage on Dharasu–Yamunotri in Uttarakhand. fiinews.com
