With the monsoon withdrawing, construction of a new barrage across the Kollidam at Mukkombu has gathered momentum.
The construction work, being undertaken at an estimate of ₹387.60 crore, began in June last. The new regulator is being constructed 75 metres away from the damaged structure on the downstream of the riverbed.
The L&T, which bagged the contract, concentrated in the first two months on mobilising men and machinery at the site, map drawing and other preparatory works. It began raising piles in August. After two months of brisk work, the northeast monsoon slowed down the progress.
Heavy discharge of surplus water from Mettur dam and subsequent opening of water into the Kollidam from Mukkombu also put the brakes to an extent. After a brief lull, construction work resumed in the last week of November.
According to PWD sources, 20% of work has been completed so far. As far as raising of piles along the proposed stretch is concerned, the officials say 45% of work has been completed. Out of 484 piles, 242 have been completed. Each pile has 1.25 diameter and it has been erected from a depth of 26 metres.
Construction of a diaphragm wall is the other major work being undertaken at the project site. It is aimed at avoiding seepage of water and arresting the movement of sand in the vicinity of the structure. Out of 1,650 metres, the diaphragm wall has been constructed for a length of 600 metre.
“Below ground level work usually faces many hurdles due to various factors. Despite brief stoppage of works for a few weeks due to water flow, there has been steady progress. It is on the right track,” said R. Baskar, Executive Engineer, River Conservation Division, Tiruchi.
The work schedule has been prepared after taking into account various factors such as water flow, monsoon and natural disturbances. The period between January and June was conclusive for construction activity. It has been planned to complete all below ground level works within May. Once these are completed, there will not be much problem in taking up above ground level structural work.
“We have crossed the crucial phase of the new regulator construction. The challenging period is over. The period from January to June offers a non-irrigation season window and the works are in full swing,” a site engineer said.
It has been proposed to build 53 piers and four abutments. Construction of piers has also been started. As many as 300 persons are involved in round-the-clock work schedule. Of them, about 100 are engineers and 200 skilled workers, the engineer added.
