NHAI mandates proof checks of complex designs

The National Highways Authority of India (NHAI) has mandated independent proof-checking of the designs and drawings by empanelled Indian Institutes of Technology (IITs), government technical institutions and reputed firms, seeking to strengthen safety checks for bridges, viaducts, tunnels and other complex structures in a new policy decision that will come into force from December 1.

A total of 471 bridges on National Highways have been identified with structural distress, of which remedial work has been completed on 159 bridges, while repairs on the remaining 312 bridges are targeted for completion by December 2028, the Union government informed Parliament in August.

The new proof-checking rules will apply to all NHAI projects where design-setting and proof-checking have not begun before December. NHAI said independent scrutiny of critical structures, including associated hydrological and hydraulic studies, was essential to ensure structural safety, serviceability, durability and compliance with applicable Indian Roads Congress (IRC) codes, specifications and provisions of concession agreements as well as address concerns around the structural safety of highway assets designed for a service life of 100 years or more.

Under the revised framework, contractors or concessionaires must appoint an independent design proof-checking consultant from NHAI’s empanelled institutions and firms. The consultant will review design calculations, structural drawings and, where applicable, hydrological and hydraulic assessments, before the designs are submitted for approval.

The policy also introduces a standardised checklist covering geotechnical investigations, foundation design, structural analysis, loading conditions, seismic assessments, scour protection, drainage arrangements and the consistency of drawings with design calculations. Separate checklists have been prescribed for major bridges and other critical structures.

NHAI said the cost of proof-checking for EPC, HAM and BOT projects would be borne by the respective contractor or concessionaire. The process must be completed within the stipulated timelines, and delays will not automatically entitle contractors to an extension of time or other claims against the authority.

The circular also specifies that existing contractual provisions governing proof consultants will continue to apply to structures outside the scope of the new policy.