Indian Express 13.12.2010
Can’t read radar data, BMC digs for easier tech
Stuti Shukla Tags : Brihanmumbai Municipal Corporation, Ground-Penetrating Radar, GPR Posted: Mon Dec 13 2010, 04:46 hrs
Mumbai : The Brihanmumbai Municipal Corporation might not have found a solution yet to the recurring problem of road cave-ins, but it has already abandoned plans to use the Ground-Penetrating Radar (GPR) machines to detect leaks in underground lines that cause cavities and weaken roads. The BMC now has no way of detecting leaks in underground utilities, even though the roads continue to cave in.The BMC first decided to try out GPR machines to detect cavities beneath roads and leaking utilities that cause the cavities following a cave-in along the arterial Peddar Road in April 2009. After two pilot projects last year to assess the feasibility of the machines, the plan has now been scrapped. The reason: Engineers from BMC’s roads department were unable to understand the readings produced by the machines.
Avinash Rao, executive engineer of the department, said they used the machines at various spots, but none of the engineers was able to interpret the readings. “Fortunately, we did not buy these machines or else they would have been stuck with them. VJTI College of engineering has a GPR that they used on an experimental basis on Saat Rasta at Jacob Circle, Byculla. Structwel Engineering too took it up as an experiment, but in both cases, we could not see the results. We even tried to get a software that can interpret the data, but without any success,” said Rao.
A portion of Peddar Road near Cabdury Junction caved in during April 2008 while a concrete slab on the busy Shravan Yashwant Chowk at Kalachowkie gave way in February this year. As recently as December 7, a section of the road in Kandivali, paved with interlocking tiles, caved in. All these incidents have been caused by leaks in underground utilities like water pipelines, storm water drains and sewer lines.
While sources said GPR was abandoned in February, the department has not been able to look for an alternative technology in the 10 months since. Additional Municipal Commissioner Aseem Gupta said the department has floated an expression of interest to invite firms with suitable technologies. “This is a technologically complex issue as it involves detecting underground situations which cannot be seen with the naked eye. We are trying to find better ways and have asked companies to come forward and present their technology. We will then go to the Standing Technical Advisory Committee on roads for their approval before purchasing any technology,” said Gupta.
N V Merani, chairman of this BMC-appointed committee, said unless ageing underground utilities are replaced no real solution can be worked out to prevent cavities from forming under the roads. “There are several experts in the committee, but no one is aware of any other technology that can map underground utilities and detect cavities. Till the century-old underground pipes are completely replaced, the problem will persist,” said Merani.
Old storm water drains are being replaced under the BRIMSTOWAD project and sewers under the Mumbai Sewage Disposal Project. Projects to replace parts of mains from the dams are undertaken every year.
