Nehru bridge in Ahmedabad to be hydraulically lifted
The 61-year old Nehru bridge over the Sabarmati river in Ahmedabad, weighing approximately 2,500 tonne is being closed for repair work and will be lifted by 50 mm using 20-odd hydraulic jacks.
Once raised, engineers will replace 126 of the 144 rocker-cum-roller bearings of the bridge with specialised elastomeric bearings. The various expansion joints of the bridge will also be replaced using the latest engineering techniques.
Process involved in lifting the bridge:
Hydraulic jacks would be inserted in the space between the girder (carriageway or slab) and the bridge's pillar. The girder is attached to the pillar by a system of end bearings.
Hydraulic jacks would then lift the slab with equal pressure on all sides so that the slab does not break or tilt while being lifted from the pier (pillar).
Engineers would then reach up to the pillars to replace the old bearings with the one-metre bearing. The girder would then be installed back in position by a uniform hydraulic retraction technique.
This is a rare instance of such intricate operations being carried out. The repair work will be completed within 45 days.
The bridge, which has been closed for repair work for a 45 day period, is already heavily affecting traffic around the area. Long traffic snarls can already be witnessed on Sardar Bridge, Gandhi Bridge and Ellis Bridge, three important connections to the city's nodal transport hub, agri-trading hubs and wholesale markets.
According to the Ahmedabad municipal corporation, the average traffic on the two bridges—Sardar Bridge and Ellis Bridge is estimated to be around 8,000 to 9,000 passenger cars per hour in the last few days.
The Nehru Bridge's foundation was laid in 1956 by the Chief Minister of Bombay province, Morarji Desai. Back then, the estimated cost of the bridge was Rs 50 lakh.
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