Estimation of Dynamical Forces on Turbidity Curtain in Combined Wave-Current Flow

Turbidity curtain is a kind of commonly-used impermeable device for temporal or long-term control of suspended solids or turbidity in the water column generated during dredging operations and disposing dredged spoils. This device composes of floater, ballast, and flexible curtain that is made of geosynthetic fabrics. In the case that all the curtain body, including the ballast, is in a floating status in the water, the tension induced in the curtain can be easily calculated. When the curtain is extended so long that the ballast is completely supported by the sea bottom, however, calculation becomes much more complicated when subject to combined waves and currents. The forcing on the curtain depends on both the water level difference between the two sides of the curtain and the waves and is a key factor for determining design parameters of the silt curtain, e.g. the thickness and strength of the curtain, diameter of the buoy and weight of the sinker. How to quantitatively estimate dynamic forces on this type of turbidity curtain has not been fully investigated. This study is proposed to develop analytical and numerical solutions to estimate dynamical forces on the silt curtain under currents, waves or combined current and waves.