GSI experts suggest measures to stabilise Shillai NH slopes

Ambika Sharma

Tribune News Service

Solan, August 9

In a bid to ensure stability of the slope during widening of the Paonta Sahib-Shillai section of National Highway (NH)-707, experts from Geological Survey of India (GSI) have suggested slew of precautionary measures.

Since the Himalayan terrain in Sirmaur exhibits fragile geo-environmental conditions with regards to the slope stability, these areas have been defined as “High” Landslide Susceptibility Zones by the GSI. This necessitates the need to exercise added caution while widening this highway.

A report submitted by experts on Kali Dhank area in Shillai sub-division, where a 150-m road had caved in on July 30, has suggested taking into account the geo-scientific evaluation of inherent risk and hazard specific to that spot while undertaking widening on steep slopes.

The slide was triggered due to slope saturation and abandoned quarry activities in its toe. It was heavy rains that catapulted the slide. The quarry was active till 2019.

The GSI report has suggested benching in uphill debris as well as in the rock mass, which should be carried out carefully and scientifically. Given the vulnerability of fragile strata, suggestions like installation of signboards/ banners at appropriately identified vulnerable locations for cautioning the commuters has been put forth. Widespread landslide awareness should be made in vulnerable areas to warn the dwellers.

This can help prevent loss of lives as commuters travelling on the route can be warned about the looming danger of landslides which are triggered during the rainy season. Altering the geometry of the steep slope by flattening and benching along with draining out any ingressing nallah or rain water has also been made by the GSI experts.

Since the area receives 70 per cent of annual rainfall in the monsoons, the need to exercise added caution has been stressed.

Paonta Sahib SDM Vivek Mahajan said, “The staff of the private company widening the highway as well as the officials of the Ministry of Road Transport and Highways have been directed to ensure that all measures suggested by the GSI are adhered to. It will be ensured that signage are erected at vulnerable sites to create awareness among the commuters to avert a mishap.