Silt curtains are impermeable vertical barriers extending from the seawater surface to their designed depths. The curtains are held in a vertical position by the carrier float on their top and a curtain weight at their bottom. A tension cable is designed at the carrier float to resist stresses incurred by currents. Moreover, the silt curtains are anchored to the seabed to hold them in the designed configuration.
In essence, the depth of silt curtains should not be so long and touch the seabed because the bottom segment of the silt curtains would be trapped inside the newly accumulated sediment, thus resulting in the sinking of the curtain. It is difficult to remove these sunken curtains. Moreover, reversal tidal and current actions may cause movement of bottom region of curtains which stir up the settled suspensions and create additional turbidity.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
If you have a query, you can ask a question here.