Following heavy snowfall in January and February, breakthrough in the strategic 8.8-km Rohtang tunnel project — meeting of the ends of the North and South Portals — will be delayed at least by two months as the Rohtang tunnel is again passing through a critical phase due to poor rock conditions at the South Portal.
Chief Engineer Rohtang Tunnel Brig DN Bhatt said that at present the work is going on on the South Portal round the clock despite heavy snowfall. North Portal near Sissu, on the other side of Rohtang, remains closed from December till May 15 every year due to closure of Rohtang Pass during this period.
The Chief Engineer said heavy snowfall during the previous two months has also affected traffic movement on the approach road to the tunnel though the construction work at South Portal has not been stopped at any time.
During these two months avalanche sites became active and about 145 small and heavy avalanches have been recorded in Solang Valley, Dhundi and South Portal.
However, the loss to life has been averted by restricting movement of vehicles. In view of the avalanche threat the road between Solang and South Portal remained closed for traffic from 8 am to 5.30 pm every day. This has affected the disposed of muck from the tunnel.
Brig Bhatt said the construction at the South Portal of the tunnel is passing through a high overburden of above 1100 m due to which high stress conditions are being encountered.
Also, during the two months, the rock strata encountered has been very poor, slowing down the progress. If such poor rock conditions prevail in March as well the breakthrough may be achieved only in September 2017 not in July 2017.
Story: The Tribune