BMRCL to resume next week construction of metro pillars that are over 12 meters high

Work on those pillars were stopped a month ago after a reinforcement cage fell on a moving two-wheeler killing a mother and her two-year-old son

With new safety protocols, the Bangalore Metro Rail Corporation Limited (BMRCL) will resume construction of metro pillars over 12 metres high next week. A month ago, the BMRCL stopped construction after a reinforcement cage collapsed on a moving bike, killing a mother and her two-year-old son on Outer Ring Road near HBR Layout.

Anjum Parwez, Managing Director, BMRCL, said as per the revised safety protocols, based on the height of the pillars, three categories have been identified — 12 metres high, between 12 and 20 metres high, and over 20 metres high.

“Pillars of 12-metre height will be erected with single-stage concreting, 12 metres to 20 metres with two-stage concreting, and for the rest of the tall pillars with three-stage concreting. Stage-wise concreting will ensure good support for the reinforcement pillar. Our internal team has prepared the new set of protocols, and experts from the IISc have scrutinized the same,” he said.

On the proposed Blue Line, from Central Silk Board to Kempegowda International Airport, the BMRCL will construct more than 2,500 pillars, out of which a majority of the tall pillars will be on the Kasturinagar-Hebbal ORR stretch.

The MD said 150 to 200 pillars above 20 meters would be constructed near the underpasses and flyovers on the ORR.

“Considering the safety aspects, a detailed methodology like how the reinforcement has to be placed, shuttering, tying guy wires, supporting the cage with the help of a crane, and others have been incorporated. Staged concreting will ensure the safety of the under-construction structure. For example, if the pillar is designed for 20-meter height, concreting will be done for the first eight meters, and after that, reinforcement will be continued by following the SoPs for the required height, and the second stage of concreting will be done. This will provide adequate support to the structure and ensure the stability of the reinforcement cage,” said Prof. Chandra Kishen J.M., Department of Civil Engineering, Indian Institute of Science, who has given his comments on the new SoPs proposed by BMRCL said.

Prof. Kishen added that suggestions had been made to ensure that the contractor employs experienced supervisory staff to monitor the construction in the coming days. From the BMRCL, a safety team will inspect the structure before concreting work to ensure the contractor has followed the safety methodology. The revised safety guidelines will be applicable for existing and future metro constructions.