Resumen

ALVARADO-ANCIETA, César Adolfo. Protection of erosion in sharp bends using rockfill rip-rap. Tecnol. cienc. agua [online]. 2013, vol.4, n.1, pp.51-82. ISSN 2007-2422.

To adequately design protection works for banks with bends as well as to determine the width required for navigation, a proper understanding of the flow in bends and the resulting bed topography is required. This is one of the most difficult phenomena encountered by river engineers, the main difficulty being the description of the helical flow and its impact on the channel bed. Changes in the shapes of river plants and cross-sections along with variations in river morphology due to sedimentation and erosion cause deep scour holes along the outer bends of rivers. As a consequence, the outer bank of a bend may collapse during a flood, potentially causing substantial damage to property and infrastructure located along these outer banks. Over recent decades, the understanding of physical processes in slightly curved bends has improved substantially. Nevertheless, in many rivers around the world -including many of the rivers in Peru (figure 1)- sharp bends are present and the physical phenomena in this type of bends have not yet been explored in-depth. River bends are considered sharp when the ratio between the radius of curvature R and the width B is less than 3.

Palabras llave : erosion; sharp bends; bed topography; river morphology; bank protection; rockfill protection; sediment transport; helical flow.