NHIDCL calls in experts after newly built 12 km stretch of NH-208 in Tripura develops cracks

Experts from the Central Road Research Institute (CRRI) will arrive in Tripura within two weeks to investigate extensive damage on a recently constructed section of National Highway 208, officials confirmed.

The 25.6-kilometre stretch between Kamalpur and Khowai, completed just last year, has developed significant pavement distress following heavy rainfall in August 2024. Damage now extends across approximately 12 kilometres of the project length.

"After intense rainfall in Tripura during August 2024, signs of pavement settlement were observed at various locations, particularly within the Khowai Bypass in Khowai district," said the Secretary of the Public Works Department (PWD) during a press briefing.

The highway section, which was completed on April 17, 2023, is currently under a five-year Defect Liability Period (DLP). Officials confirmed that the National Highways and Infrastructure Development Corporation Limited (NHIDCL) and the state PWD jointly manage six national highways in Tripura, covering 793 kilometres.

Field observations revealed alligator cracking and upheaval of the pavement structure at several locations. According to preliminary assessments, the failure originated in the subgrade layer.

"It has been preliminarily concluded that the failures originated in the subgrade. As per the EPC contractor's assessment, the damage was primarily due to elevated groundwater levels, which led to saturation of the subgrade soil and a subsequent loss of shear strength and load-bearing capacity," the PWD Secretary explained.

Despite the damage, officials maintain that the original construction met all quality standards.

"Comprehensive quality control protocols were followed throughout the construction phase to ensure compliance with all applicable standards. The design and execution adhered to Indian Roads Congress guidelines and Ministry of Road Transport and Highways specifications," the official stated.

Repair work is already underway, with the Engineering, Procurement, and Construction (EPC) contractor having mobilised workforce and equipment over the past two months. The rectification process includes removing and replacing soil from the embankment to depths of 1-2 metres and installing drainage barriers to prevent moisture buildup.

Officials estimate the repair work will take approximately two more months to complete, while the CRRI investigation is expected to determine the exact cause of the premature road failure.