Concern over collapse of NH embankments, sinking of bridge pillar in Ernakulam

The collapse of parts of embankments at multiple locations on National Highway 66 that is being widened in Kerala and the recent sinking of a pillar of the Kottappuram-Muthakunnam bridge on the NH stretch in Ernakulam due to suspected faulty piling point to the need for strict adherence to the Indian Roads Congress (IRC) norms, according to experts in the sector.

Such developments have in turn given rise to uncertainty over the deadline for completing widening of NH 66. While the National Highways Authority of India (NHAI) has begun repairing the damaged embankments and the ensuing cracks on the NH carriageway and service roads, the contracting firm that undertook the bridge work has roped in a specialist firm to suggest remedial action to be taken to reinforce the damaged bridge pillar, it is learnt.

Official sources said that the firm was expected to submit its report in a week, following which NHAI engineers would inspect the structure. “This would be followed by load-bearing and other tests to assess the condition of the bridge. The ongoing NH widening works adhere to the IRC norms, and efforts are on to rectify the other damaged portions as well,” they added.

Delay, cost overrun

Expressing concern over the possible delay in completing the widening of NH 66, Yacub Mohan George, a former Deputy Chief Engineer with the Public Works department (PWD), said such defects on the NH that was being redeveloped would enhance the project cost, which in turn would lead to increase in toll rates. “The NHAI is responsible for the malady since the defects point to faulty soil investigation, while geotechnical recommendations failed to address the possibility of slippage. While NHAI personnel ought to supervise the works, the concessionaire ought to ensure the quality of construction. The independent consultant too is responsible for the state of affairs,” he said.

Load testing

Mr. George said all the newly constructed bridges built by the NHAI on NH 66 must be load tested. Maintaining that reinforced earth walls on roads require solid base, he said the NHAI must ensure that all such structures adhere to the IRC norms. “In addition, the support of PWD engineers and those familiar with the soil structure across the State must be sought for works like the construction of embankments and bridges. Third-party inspection too must be done to ensure ride quality and black spot identification. Above all, bridges must be inspected twice each year with the help of drones and underwater videography,” he said.

Seeking speedy remedial measures, Ebenser Chullikat of Greater Cochin Development Watch, an NGO, said that apart from the recently detected bridge fault, cracks had been detected earlier at an embankment in Varapuzha. “Viaducts must be built in such places, while the NHAI must doubly ensure the load-bearing capacity whenever red soil is mixed with river sand and used in embankments,” he added.