The Indian Institute of Technology-Guwahati (IIT-G) has recommended that heavy-loaded vehicles should not be permitted to ply on Umiam dam bridge until retrofitting of “distressed members” which included girder beam and deck slab and that the maximum permissible load of the bridge should be 15 tons.
Following this report, East Khasi Hills District Magistrate Rosetta Mary Kurbah has prohibited the plying of heavy vehicles exceeding the load of 15 tons from Shillong towards Umiam and vice versa.
The prohibitory order was issued for restricting the loading capacity of heavy vehicles to avoid further damage to the Umiam dam bridge which connects East Khasi Hills and Ri-Bhoi.
According to the order, heavy vehicles exceeding the load of 15 tons should proceed towards Shillong By-Pass through Mawryngkneng.
After seeing the report of IIT-G, the Power Department last week has advised the authorities that heavy-loaded vehicles should not be allowed to ply from the Umiam dam bridge until necessary retrofitting is carried out and the maximum permissible load for the Umiam concrete bridge should not exceed 15 tons.
The notification from the Power Department states that the report from IIT-G has recommended that “heavy-loaded vehicles should not be permitted until retrofitting of distressed members (i.e girder beam and deck slab)” and that the maximum permissible load of the bridge is 15 MT”.
In light of the IIT-G recommendations, the Power Department has requested the revision of the standing order regarding the gross weight of vehicles plying over the bridge.
This revision entails imposing restrictions on heavy-loaded vehicles, ensuring that the gross weight does not exceed 15 tons, as opposed to the previous limit of 20 tons.
This revision has been emphasised as a top priority for immediate implementation.
Umiam bridge is the major lifeline of the State and interconnects several north-eastern states. Concerns have been expressed over the safety of the bridge which was built in 1965.
To assess the condition of the concrete gravity dam of the Umiam bridge, a study on the traffic condition and vibration measurement was conducted by the Central Water and Power Research Station (CWPRS), Pune and the Ministry of Water Resources, River Development and Ganga Rejuvenation. A separate study was also carried out by IIT Guwahati.
The studies found that the vibration was still under control level limit. However, they had suggested retrofitting of the bridge so that it can withstand the increased vehicular movement.
In May 2022, the Meghalaya High Court had directed the State government to ban vehicles carrying loads of more than 10 metric ton from plying over the Umiam bridge following suggestions by the National Highways Authority of India (NHAI) and the Border Roads Organisation (BRO) that the existing bridge may not be able to bear the present traffic load.
