Riprap

Riprap, also known as rip rap, rip-rap, shot rock, rock armor or rubble, are man-placed rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour and water or ice erosion. Common rock types used include granite and limestone. Concrete rubble from building and paving demolition is sometimes used. Riprap, also known as rip rap, rip-rap, shot rock, rock armor or rubble, are man-placed rock or other material used to armor shorelines, streambeds, bridge abutments, pilings and other shoreline structures against scour and water or ice erosion. Common rock types used include granite and limestone. Concrete rubble from building and paving demolition is sometimes used. Underwater, riprap caps submerged tunnels to protect against accidental anchor strikes or sinking debris.