Border Roads Organisation, India
Online published on 29 March, 2018.
The Rohtang tunnel is the important road tunnel in the Himalayas providing all weather connectivity between Manali and Keylong, the head quarter of Lahaul-Spiti District. The 8.8 km long tunnel consists of a uniformly dipping alternate sequences of quartzite, quartite schist and quartz-biotite schist with thin band of phyllite with an average overburden of about 600 m and maximum to 1900 m. The complexity of the area has been increased due to problems of squeezing, swelling, sudden ingress of water, running/flowing ground, hot temperature condition in rocks. Major folds and faults are present in and near the vicinity of Rohtang tunnel and at many places are heavily charged with underground water indicating complex geology of the area. During the construction of Rohtang tunnel problem faced and remedial measure adopted has been briefly described in this paper.
