By Lynda Myer
In order to releasing the 41 workers still are trapped following a part collapse in the Silkyara Bend-Barkot Tunnel in India, preparations are undergoing to construct vertical shafts.
According to ITA president Arnold Dix’s report to T&TI: “Several options were being considered, including vertical shafts. Preparations for vertical options are under way. Multiple concurrent options, including horizontal access, were being considered.”
Due to boulders that blocked the auger, creating an escape route by jacking a 900mm-diameter pipe through the collapse debris as well as digging an 800mm auger, which were the initial solutions, failed.
Through a jacked 120mm diameter steel pipe food, water and oxygen are supplied for workers.
Additionally, Himalayan region’s geology is very complex and the rescue operation is encountering a mixture of soft ground and hard boulders.
With intention of providing an all-weather route to decrease travel distance by almost 20km between Dharasu and Yamunotri, the 4.5km Silkyara Bend-Barkot Tunnel is being developed for National Highways and Infrastructure Development Corporation (NHIDCL).
