Solan: There is no let up in the erosion of debris from the fragile excavated hill all along the Parwanoo-Solan stretch of National Highway (NH)-22 which was being four-laned since September 2015.
The maximum erosion was witnessed during the rains all along this highway. However, even after the monsoons have subsided the erosion is persisting. There are several vulnerable stretches near Datiyar, near Koti railway crossing and near a hospital building at Dharampur where the loose clay was eroding from the hill in large mounds.
Though some work was under way to contain the erosion at Dharampur near a petrol pump the breast walls constructed below had collapsed a few days ago.
As many as six houses lying atop the excavated hill had also become vulnerable during the rains when large-scale erosion had taken place at their base. The families had been directed to shift to safer places by the district administration during the rains as wide cracks had appeared in these houses.
Officials of the NHAI, when contacted, said that a team of geologists from the Geological Survey of India had been asked to conduct investigations at Dharampur and as per their recommendation shotcrete and rock bolting would be undertaken to contain erosion.
The officials added that the GR Infraprojects, which was executing this four-laning work, has been directed to adopt this method at Dharampur site near the hospital as well as other such vulnerable sites including the one near Koti railway station.
Rock bolt is a long anchor bolt, for stabilizing rock excavations, which may be used in tunnels or rock cuts. It transfers load from the unstable exterior to the confined (and much stronger) interior of the rock mass. Shotcrete is the process of placing concrete to achieve high strengths and low permeability. The use of these techniques is supposed to help contain the large scale erosion opined experts.
While the four-laning work is at an advanced stage, containing erosion has become a Harculean task for the executing company. With an entire hill threatening to crumble near Datiyar due to the fragile strata, stabilizing the hill has become a major challenge for the GR infraprojects .The lane facing the hill has failed to become functional due to the falling debris at such sites.
Assigned 30 months for the execution, the project was already running behind schedule. The project officials were hopeful of completing the major work in March though about only 55 per cent work has been completed till now.
