KOCHI: In the wake of damage along several newly-constructed NH 66 corridors in northern Kerala, including a major incident at Kooriyad in Malappuram district, the National Highways Authority of India (NHAI) will issue guidelines to prevent similar occurrences at other project sites in the state.
NHAI revealed that a section of the service road and retaining wall collapsed at Kooriyad due to the concessionaire’s negligence in assessing ground conditions and improving the ground’s bearing capacity prior to commencement of work.
This was revealed in a report submitted by NHAI to the High Court in connection with the Kooriyad incident. The HC had directed the authority to file an interim report on the incident.
According to the authority, a team of two experts under the supervision of a retired professor from IIT Delhi visited the site to study the incident and suggest remedial measures. Based on the measures suggested by the team, work will be executed at the risk and cost of the concessionaire. Additionally, the expert team will suggest measures that could be taken for other ongoing projects in Kerala. “Guidelines will be issued so that such incidents do not occur in other projects being implemented in the state,” the report said.
NHAI said that according to the preliminary assessment of experts, Kooriyad was likely caused by the inability of foundation soil to support high-embankment loads. “... the failure could be due to the weak nature of the sub-soil (loamy) and the water logging conditions on left hand side (LHS) of right of way, since the paddy field and flow of waters is from LHS to RHS (right hand side).
The expert team also noticed that the failure was caused on the upstream side of the reinforced earth (RE) wall and no damage on the downstream side of the RE wall,” it said.
The report pointed out that construction work of the RE wall between the minor bridge and the vehicular underpass is being carried out as per the concession agreement. Bore holes were constructed during fair weather to assess and reports of respective boreholes were shared with the designers in a timely manner to understand the ground conditions and to provide necessary design for structures.
The authority added that it is taking steps to restore traffic on the RHS service road by reducing the height of the RE wall, which is being taken up on war footing. Necessary measures, including reconstruction, shall be taken up as per the recommendation of the expert committee.
Action taken by NHAI
Project consultant/independent engineer/highway engineering consultant disallowed from participating in ongoing/future bidding
Project manager of concessionaire and team leader of consultant suspended from their duties
KNR Constructions Ltd disallowed from participating in ongoing/future bidding