The State government has sanctioned ₹38.85 crore for construction of sheet pile walls across the Kollidam at Mukkombu.
A Government Order to this effect was issued recently.
The project is aimed at preventing soil erosion and and water leakage through the temporary bunds built along the damaged regulator that was washed away on August 22.
Senthil Kumar, Chief Engineer, Water Resources Department, Tiruchi region, told The Hindu that tender had been invited for executing the project. The tender process would be over within the first week of January. Work order was expected to be given to the successful bidder in February. It had been decided to complete the project within three months from the date of issuance of work order.
Under the project, sheet pile walls would be constructed on both upstream and downstream of the temporary bunds built across the Kollidam. While the sheet pile wall on the downstream would run for 650 meters, it would be constructed for 126 meters on upstream.
The sheet walls would be constructed by driving pre-fabricated sections into the ground. They would be formed by connecting the joints of adjacent sheet pile sections in sequential installation. It was aimed at ensuring the stability of temporary bunds and the remaining portion of the regulator.
Mr. Kumar said the sheets would be installed by penetrating into the ground for a maximum of 7 meters from the bed level. The sheet piles would be cemented and interlocked with masonry structure wherever it required.
Asked about the need for the project when temporary bunds had already been constructed along the damaged regulator, the Chief Engineer said it was noticed that 200 cusecs of water was being leaked into the Kollidam through the gaps of bunds. Moreover, there was soil erosion due to constant water leakage. The sheet pile walls would not only arrest soil erosion but also water leakage.
Mr. Kumar said one of the sheet pile walls would be built between the existing regulator and the proposed new one. It would also act as a protective mechanism to the new regulator. The proposed sheet pile walls would improve the stability of existing structures.