A day after the collapse of the floodlight tower in L.B. Stadium, the predominant concern pertains to the condition of the remaining three towers.
On Monday night, one tower crashed under the impact of strong winds, and fell on two passers-by, killing one and injuring the other. Since then, questions are being raised about the structural stability of the towers and their ability to withstand winds. GHMC Commissioner M. Dana Kishore has issued notices to the Sports Authority of Telangana State (SATS) on Tuesday, asking them to get the remaining towers evaluated by engineering experts from either JNTU-H or Osmania University.
“If the remaining towers are found weak, we will have to take measures to get them removed as soon as possible, to avoid future mishaps,” Mr. Dana Kishore said. Besides, the corporation has also issued notices to all the mobile phone service providers to get their respective towers across the city checked and submit the reports.
Guidelines with regard to structural stability of towers vis-a-vis zone-wise wind pressure are prescribed by the CBIP (Central Board of Irrigation and Power) manual, and are adhered to across India, an engineer from the TSTransco informed. Wind pressure in Telangana region, as mentioned in the manual, is about 44 metres per second, which needs to be kept in mind while designing towers here. As per the Meteorology officials, the highest wind pressure recorded at the Begumpet Airport on Monday was 20 metres per second, which is within the tolerance limit of the well-designed towers.
Besides the base strength, there could also be other factors such as metal used, and maintenance of the tower that play their part in weakening of the structure. “The approved measurements may have been compromised during erection, or rust could have generated weak points in the tower. The foundation needs to be regularly checked for repairs and periodical grouting should be done,” the engineer said. One more important factor, he said, could be the ‘Wind Funnel Effect’, which refers to the increased wind pressure when passing through narrow spaces.
“Many structures have come up in the vicinity, after the towers were erected, thus narrowing down the spaces, and giving scope for funnel effect,” he theorised. The towers were erected in 1991, and are 120- to 130-foot high with a base of about 150 square feet, VC-MD of SATS Dinakar Prasad said.
Meanwhile, the debris from the tower is yet to be cleared from the stadium, one day after the collapse. Mr. Dana Kishore informed that it will be cleared by the GHMC’s disaster response team on Wednesday, after SATS hires a crane large enough to lift the tower. “We have advised them to hire the cranes deployed for Ganesh immersion. Our men will remove the debris once the crane comes,” he said.
Police were posted at two gates leading to the stadium, and other entry points were locked. When enquired, Mr. Dinakar Prasad said regular members were being allowed, and outsiders are routinely denied entry.
