Polavaram diaphragm wall work done in record time

Marking an important milestone in one of the country's largest multi-purpose project ‘Polavaram” in Andhra Pradesh, the work on the diaphragm wall which forms the foundation for the Earth-cum-Rock-Fill (ECRF) dam, has been completed in 414 working days.

The dam will be built 150 feet high to store 194 TMC of water. The diaphragm wall that is constructed below ECRF prevents the leakage of water across the dam from the bottom of ECRF through sand pores.

Chief Minister N Chandrababu Naidu on Monday unveiled a Pylon at the project site, marking the record making event. Describing the project as the lifeline of the state, Naidu said that the project is finally taking shape after overcoming several hurdles. “I congratulate the engineers and the workers for achieving the feat within a record time of 414 working days (79 days flood season in between) from 1 February 2017 when I laid the foundation,” he said addressing farmers drawn from 13 districts of the state. The Chief Minister has so far conducted 25 physical inspections and 63 virtual inspections.

He said that the project will be completed by the end of 2019. “Once completed, the dam will be able to irrigate 7 lakh acres in the state,” he said. He assured that his government will actively pursue the interlinking of rivers by linking Vamsadhara, Nagavali, Penna and Godavari to provide irrigation to hitherto dry tracts of the state.

The diaphragm wall unveiled on Monday is around 5 feet thick, about 1,400 meters long and at a depth of about 130 to 307 feet below the ground. By deploying the latest German technology, the diaphragm wall is constructed using a special clay construction material called ‘bentonite’ to make it waterproof. This will facilitate hassle-free construction even during the flood season without any leakages or breaches.

Over 2,500 workers and 500 engineers worked on a mission mode to complete the diaphragm wall. Polavaram, a multi-purpose project being built on River Godavari, though conceptualized in 1941, gained pace in construction after 2014.