Construction Methodology of Intake Well by Well Sinking Method.

      Construction Methodology of Intake well by Well Sinking Method.

          Introduction: Circular Intake Well of 14m internal diameter is being constructed to draw water from Ujani Reservoir for NTPC Solapur Super Thermal Power Plant 2X660MW. Four Openings will be there at two different levels.

These are the following Steps for Construction of Well-

1)Construction of Temporary Island in the reservoir where ever the well is to be constructed as per geotechnical investigation.The Dia of Island should be three times the External Dia of Intake Well. Mainly the island is filled with earth upto desired level considering the High Flood Level of the reservoir.The main purpose of Island is for working platform for the Well.

 Earth Filling for Temporary Island with Locally available Material.

Key Points to remember while earth  filling for Temporary Island-

>Avoid Boulder filling. While dumping all the boulders will come to bottom by weight and there will be a boulder layer at the bottom of the island.Which will reduce the efficiency of sinking when we reach the bed level.

>While increasing the dia of island by dumping, clay should be dump for one layer of around one meter followed by another available material two or three meter respectively expect the exact location of the well. Clay material  will act like a grout material and it will be very helpful while dewatering for sinking of well by decreasing the percolation of water.