After the SK MOST Group of Companies commissioned the Krolsky Tunnel in 2011 within this section, and the Mansky Tunnel was inaugurated in August this year, JSC STROY-TREST is currently conducting reconstruction of the Dzhebsky Tunnel.
Compared with the Mansky and Krolsky tunnels, the Dzhebsky tunnel does not stun with its size. The tunnel is 660.8 meters long; however, it is located deep inside the Sayan mountain range at an altitude of 700 meters above sea level.
Snow can fall as early as in the last week of August there and would stay until the beginning of next summer, with the snow cover being of up to 1.2 meters thick. Given such environment, the first priority was to provide comfortable life and work conditions for tunnel builders. A small camp was built, and the work is underway to improve the access roads to the western and eastern tunnel entry sites.
The builders are going to remove the old lining, enlarge the tunnel cross-sectional area and start waterproofing and new lining installation, all until 2016. By the commissioning date, the tunnel entries will be completely refurbished, the tunnel innards and all utility systems from drainage to lighting, to ventilation will be upgraded. A continuous welded non-ballasted low-vibration track will be installed on an LVT-system rigid bed. The LVT half-sleepers are rubber-cased and provided with shock-absorbing pads for vibration reduction.
The tunnel is reworked by drilling and blasting. Highly frost-resistant concrete mixes and earthquake-resistant design concepts (designed to withstand an up to 7.0 points earthquake) are used.
Sergej Berdnikov / SK MOST