Document Type : Research Paper
Author
Assistant Professor, Soil Conservation and Watershed Management Institute, Tehran, Iran
Abstract
One of the common methods of river training and bank protection is using spur dikes to modify flow path. Because of the concentration of flow in the middle part of the river it causes the river side not to be washed out. This new river path makes the river bed next to the end of the spur dikes to be washed out. Usually the spur dikes are built in groups to extend the protected zone. The stability of these spur dikes against the river flow depends on stability of the first spur dike. The purpose of this laboratory research is to investigate different ways for reduction of erosion around the first spur dike. It is suggested to use a shorter spur dike at the upstream part perpendicular to the flow direction. In this research, it is intended to find the optimum distance between the shorter spur dike and the first spur dike in order to have minimum erosion around the first spur dike. From the hydraulics point of view, L’/L (the length of shorter spur dike to the length of first spur dike), X/L (the distance between first spur dike and shorter spur dike to the length of first spur dike) and H/L’ (the depth of water at upstream to the length of shorter spur dike) have been studied and results has been presented in the form of equations.
Keywords
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