NHAI ropes in experts to find solution for slope protection

Ambika Sharma

Solan, February 1

In a bid to find an effective and lasting solution to protect the eroding slopes on the damaged Parwanoo-Dharampur section of National Highway-5, the National Highways Authority of India (NHAI) has roped in several experts.

While it has recently signed a memorandum of understanding with the Satluj Jal Vidyut Nigam (SJVN) in view of their expertise in the hills, assistance of geologists has also been sought to study various aspects, which effect slope protection.

Vulnerable spots being geo-mapped

• The geo-physical testing of the vulnerable spots like Chakki Mor is being undertaken whereby ultrasonic waves are sent to a particular stretch and its response is interpreted to know the thickness and properties of various layers
• The experts are also undertaking geo-mapping of the vulnerable spots to know if there was an active fault line in a hill. Presence of a fault line makes an area vulnerable to erosion and such areas require adoption of technologies for slope protection

NH-5 had suffered colossal damage

• The Parwanoo-Solan stretch of the National Highway-5 suffered colossal damage due to 426 per cent excess rain that had pounded various parts of Solan district last monsoon
• As against the normal rainfall of 76.6 mm, 249.6 mm average rain was received in the state from July 1 to 11. Cloudbursts in the vicinity of the Parwanoo-Solan highway resulted in flashfloods and massive landslides

Abdul Basit, Regional Officer, NHAI, Shimla, said: “Geo-technical investigations of vulnerable strata is being undertaken by experts, including Dr Amit Verma from IIT-Patna. Investigations like boring are undertaken in the soil and rocks to ascertain various aspects like soil consistency, groundwater level, etc., of a site. This will prove helpful in suggesting engineering technologies for permanent restoration of the damaged slopes.”

Apart from this, geo-physical testing of the vulnerable spots like Chakki Mor is also being undertaken whereby ultrasonic waves are sent to a particular stretch and its response is interpreted to know the thickness and properties of various layers, including the presence of a water body.

Leaving no stone unturned, the experts are also undertaking geo-mapping of the vulnerable spots to know if there was an active fault line in a hill. Presence of a fault line makes an area vulnerable to erosion and such areas require adoption of appropriate technologies for slope protection. Notably, the manner in which a sizable section of the hill at vulnerable places like Chakki Mor had eroded has forced the experts to undertake its geo-physical investigations.

“While such an investigation has been completed on the hill side at Chakki Mor, the same will now be undertaken on the valley side where efforts were afoot to create space to station requisite machines,” said Basit.

He added that a team of experts from the SJVN has also visited the vulnerable spots on the Parwanoo-Dharampur stretch and they have given valuable suggestions. “Tenders for slope protection would be floated after the geo-technical and geo-physically investigations are completed so that experts can suggest permanent solution to protect the slopes as safety of the commuters is our prime concern.”