الفهرس 
introductionOnly 14 pages are availabe for public view
 |  | from | 192 |  |  |
| | | from | 192 | | |
Abstract
Spur dikes are common river training structure, it helps in river banks protection by diversion the flow away from banks. However, the existence of dikes lead to constriction of the river cross section. So, the velocity increases around spur dikes causing scour hole, which threats the safe of the structure. So, in this thesis the estimation of scour hole dimensions around spur dikes was studied.The experiments were carried out in the hydraulics laboratory of faculty of engineering, El-Mansoura University- Egypt. This research focused on a comparison of five configurations of spur dikes as straight, hockey, mole head, L-shape and T-shape and their effect on the scour geometry. All models have a contraction ratio of 0.2 from flume width. Each run was performed until scour reached the equilibrium state.A total number of one hundred runs were carried out, four discharges were used on each model. For every discharge, there were five water depths for estimating the maximum scour depths and horizontal dimensions of scour hole around the chosen spur dikes shapes.For analyzing the collected data, many relationships, graphs and contour maps were obtained using many programs. The effect of flow characteristics such as Froude number, flow discharges and comparison between models was investigated under the clear water condition. Equations for predicting the maximum scour depth and horizontal dimensions for each shape were determined using SPSS software.A general equation was developed for any shape of spur dikes as a function of both Froude number and shape factor, this equation was determined by either percentile or coding methods.The results indicated that hockey shape shows better performance in scour depth reduction. However, straight shape has undesirable impact as the largest scour hole is formed around this shape. For all layout of spur dikes when Froude number increases the depth of scour or relative scour depth increases for all discharges.Horizontal dimensions increase when Froude number increases; however, the increase of discharge doesn’t have a uniform pattern. For future work, it was recommended studying the comparison of the chosen shapes with different contraction ratios lengths and median grain sizes as a single spur dike or in series.