Abstract: A system for alleviating scouring damage at the base of a structure anchored in the bed of a body of liquid flowing at a velocity relative to the structure, such as a bridge pier in a river bed, comprises a plurality of hollow vehicle tires surrounding the structure in a matrix of plural stacks of tires connected together with their toroidal axes substantially aligned. Each stack comprises a predetermined number of tires so that the top surface of the matrix forms a predetermined angle relative to horizontal.

Abstract: An actuating device can change a position of an active member that remains in substantially the same position in the absence of a force of a predetermined magnitude on the active member. The actuating device comprises a shape-memory alloy actuating member for exerting a force when actuated by changing the temperature thereof, which shape-memory alloy actuating member has a portion for connection to the active member for exerting thereon a force having a magnitude at least as large as the predetermined magnitude for moving the active member to a desired position. Actuation circuitry is provided for actuating the shape-memory alloy actuating member by changing the temperature thereof only for the time necessary to move the active member to the desired position.