WHAT IS THE SOIL IMPROVEMENT TECHNIQUE USED WHEN THE SOIL DONOT HAVE ADEQUATE STRENGTH AND IS PERMISSIBLE TO FLOODING AT REGULAR INTERVALS ?

Firstly,u dint mention the type of the soil! u must drain out the water  to enhance the strength.i agree with u on providing geosynthetic fibre for strength improvement!

It may be by sand filling,As the percolation of water would be more efficient in the horizontal direction is more than in the vertical direction.In addition to this providing geo synthetic fibres in between and providing necesssary drainage by use of water absorbing substance connected to the water table so that it would reach the ground water table.By doing this water would not flood and water would be properly drained out