Analyses Of Pier Scour Plate Structure Control Factors And Model Optimization

Ring wing type baffle plate is a way to reduce the local scour at Piers.this paper is based on the previous research results. The influence factors of preventing plate local protection mainly in the shape (long axis and short axis) and the installation location.In view of reducing the scour depth and decreasing vertical velocity of pier bottom, building the pier scour plate model in the laboratory, analysis of variance and range analysis, to study primary and secondary relationship of three controlling factors in scour plate. And a detailed analysis of the maximum scour depth, hydraulic characteristics, hydraulic turbulence of pier top about the impingement plate the installation position. In addition, the influence of the installation position and shape combination on the maximum scour depth and the hydraulic characteristics of the pier are also analyzed. Through analyzing the test data, draw the following conclusions:(l)Test respectively to the scour depth and the pier near bottom vertical velocity as the index, the relationship between primary and secondary pier scour in the three control factors and significant for the installation location> long axis>short axis, and that the effect of little short half axis. Considering the factors of influence on saving navigation ability as well as the material, The optimum combination of the test model is 0.2depth length half shaft length 2radius,and short half axle for 1.4radius.(2)The maximum scour depth and near bottom turbulence intensity is mainly associated with the impingement plate related from sand bed distance.(3)When Baffle plate installed under 0.5h,region above Baffle plate appear the high velocity, and at this point baffle plate subjected to large impact force.(4)The installation position is not play a decisive role in scour depth.When the baffle plate shape is very small, even if the installation position is the lowest, the maximum scour is still depth.(5)Position of falling flow before the pier is not far from pier but along the pier, the lower water will tilt into the scour hole and shock the sand bed.