Doubts over safety of Telangana\'s Laknavaram, Karimnagar bridges after Morbi tragedy
WARANGAL: Morbi tragedy in Gujarat that led to deaths of 134 persons has triggered fears about the safety of similar bridges at Laknavaram in Mulugu district and cable-stayed bridge in Karimnagar district.
Thousands of tourists visit Laknavaram in Govindaraopet mandal not only to enjoy scenic beauty of the Laknavaram Lake dotted with 13 small islands, but to also have the experience of walking over the 180-metre suspension bridge constructed over the lake.
Laknavaram suspension bridge engineer Rama Krishna has dispelled fears about the safety of the bridge, pointed to the regular checks that are carried out. The lake has two suspension bridges, one constructed in 2008 and the other in 2018. The bridges have been constructed with ISI-standard ropes and cables imported from Korea and steel from Visakhapatnam.
The bridges are suspected from huge main cables and long ropes extending from one end of the bridge to the other. The cables rest on top of high towers anchored into the bank at either end of the bridge. The weight or load on the bridge is transferred by cables to the anchorage systems embedded in either solid rock or huge concrete blocks.
Maintenance of the bridge is with an agency whose staff check nuts and bolts every two days, tightening the threading wherever necessary. Rama Krishna said the entire bridge is also checked at regular intervals.
The cable-stayed bridge across Manair River is very different compared to suspension bridges, where decking is held with vertical suspenders that go up to the main support cable. The most commonly used materials are steel or concrete pylons, post-tensioned concrete box girders and steel rope. These bridges can support almost every type of decking.
The state government had taken up construction of the cable-stayed bridge at a cost of ₹187 crore in 2018. Works are being grounded by Tata Projects and Gulemark, a Turkey-based company. The bridge is coming up with two huge pylons measuring 220 metres, along with 680-metre length four-lane roads and footpaths for pedestrians.
Load testing had been carried out on this bridge under the supervision of executive engineer Sambasiva Rao. Total 28 tippers, each weighing 840 tonnes and filled with 30 tons of sand bags, had been placed on the bridge. In addition, sandbags weighing 110 tonnes had also been loaded on footpaths along either side of the bridge.
Engineers checked the bridge for deflection for every hour by arranging sensors at seven places under the bridge for a few days to make the necessary adjustments.
However, the check dam constructed at the cable-stayed bridge costing ₹30 lakh got washed away when floodwaters from Lower Manair Dam were released last year, posing a threat to the bridge. The road that leads to the cable-stayed bridge is also in poor condition.
City Congress president K. Narendar Reddy held the TRS government responsible for washing away of the check dam, as for sake of commissions, contracts had been handed over to persons who used poor quality materials that did not withstand the floodwaters.
