Pune: Work to install additional rockfall protection at Pune-Mumbai expressway’s Connecting Link, which was recommended by IIT-Bombay after a major landslide in July, will now be finished by Nov, officials said, revising the earlier Sept-end deadline that was set in Aug.Officials from Maharashtra State Road Development Corporation (MSRDC) told TOI on Tuesday the reinforcement work — using a high-tensile steel mesh and steel barriers — was primarily aimed at securing the hillside and stopping large boulders from reaching the carriageway. This work is now about 30% complete, the officials said, adding that heavy monsoon in the area had slowed progress.The July 6 landslide, which led to a 20-hour traffic jam on the expressway, had sent large boulders crashing onto the road near the mouth of Tunnel 2, damaging a false frame at its entrance. Officials estimate some of the rocks that fell weighed 17-20 tonnes. Water emerging from newly formed channels on the hillside also flowed onto the Mumbai-bound carriageway.“But the steel mesh, procured from Switzerland, has been designed to contain loose rock and prevent them from reaching the road. The steel barriers will provide an additional line of defence against larger rocks that could dislodge from higher elevations of the hill,” a senior MSRDC official said.The collapsed frame has been reinstalled as part of short-term measures. “The short-term measures are being sped up, but mesh installation will need time,” another senior MSRDC official said. The official added that installation could not be executed at full pace due to heavy rain. “Drilling, anchoring and mesh installation require relatively dry conditions. With the monsoon easing, rest of the work is being accelerated and is expected to be completed by Nov,” the official said.A few days after the landslide, the site was inspected by a geotechnical and engineering team from IIT-Bombay, which examined the hillside and recommended a series of measures to strengthen vulnerable sections. Officials said the reinforcement work along the sections was being designed for an extreme weather event with a 1-in-1,000-year probability, compared to the 1-in-100-year benchmark that was adopted for the Rs 6,695-crore Connecting Link’s original protection system.
