The Ahmedabad Municipal Corporation (AMC) has initiated a six-month closure of the historic Subhash Bridge after officials discovered alarming cracks and a structural settlement, prompting immediate safety concerns.
Immediate Closure and Inspection
The decision to close the 52-year-old bridge came swiftly on Thursday, November 16th. The action was triggered around 4:30 PM when AMC officials, during a standing committee meeting, received a complaint about a visible crack. Officials promptly left the meeting to inspect the site. They observed a significant crack and a settlement in one span on the bridge's left side. Consequently, the bridge was officially closed to all motorists by 6 PM on Thursday.
Detailed Assessment Reveals Extent of Damage
On Friday, a comprehensive inspection was carried out by AMC officials along with consultants from the state government's road and building department. The team identified a specific issue: the slab above Pillar No. 9 had settled. A large crack was visible on the upper slab on the left side, on the path leading from Shahibaug towards Subhash Bridge Circle. Cracks were also found on the parapet and were noted to be widening.
To get a complete picture, officials employed innovative methods. Drones were flown to capture visuals from above, and a boat was used to inspect the underside of the bridge structure. The initial inspection revealed that, prima facie, the pillars of the bridge are not damaged, and there appears to be no effect of vibrations on the pillar sections.
Advanced Testing to Determine Concrete Health
However, the settlement of the slab has raised suspicions of potential internal damage to the other slabs. Therefore, the AMC has decided to conduct more than five rigorous tests on all six slabs of the bridge. The key tests include:
- Ultrasonic Pulse Velocity (UPV) Test: This non-destructive test determines the state of concrete by gauging the speed of ultrasonic sound waves passing through it.
- Concrete Core Test: This involves extracting core samples from the concrete to assess its compressive strength and internal composition.
A detailed report based on these tests is expected to be submitted within the next three days. This report will be crucial in deciding whether and how to repair the damaged slabs.
Long Closure and Historical Significance
An AMC official stated that the repair work, whether it involves the affected span or other necessary works, is likely to take at least six months. Therefore, the bridge will remain closed for this extended period. The Subhash Bridge, a vital artery in the city's traffic network, was constructed by the AMC in 1973. The bridge is 453.7 metres long and 12.8 metres wide, and its closure is expected to cause significant traffic disruptions in Ahmedabad.
The official added that after the tests are completed, it will be determined precisely what repairs are required to restore the structural integrity of this important city landmark.
