HYDERABAD: Sinkholes on major city roads have exposed the sub-standard works by road contractors selected by the GHMC. N. Raghuma Reddy, a former chief engineer of Roads and Buildings Department, said: “Contractors responsible for road construction do not follow quality engineering in order to save money. When a road is dug up for laying of a pipeline, the dug-up portion should be filled with either sand or fine dust or chips of granite stone. But the contractors fill using the cheaper option of excavated mud. When it rains heavily and water percolates, the soil stops supporting the road.”
Missing camber is another problem. Camber is a curve that’s provided to stop water stagnation on roads. Mr Reddy added: “Road rollers should be moved on road when it is still hot, preferably around 120°C, because the particles get compressed leaving less space for water seepage. This reduces thickness of the road. But contractors, move the road rollers when the tar is a little cold so that its thickness does not dip — to save money.”
Dr N.V. Ramana Rao, professor with JNTU-Hyderabad, said: “The best example is airport runways, which face the impact of planes but have a long life. Cement or concrete roads are also good alternatives but, in that as well, specifications need to be maintained.”
Satellites to track violators
Municipal Minister Mr. K. T. Rama Rao said on Friday the GHMC will be taking images of the nala network using satellites. He said the images would help identify encroachments.
A tribunal will be constituted to look into encroachments after a Cabinet-level meeting — to be held on September 26. A separate committee is also being planned — comprising the joint collectors of Ranga Reddy, Hyderabad and other officials. This Committee is expected to decide on how many un-authorised structures actually exist.
