Temporal Variation of Scour Hole around Spill Through Bridge Abutments at Various Contraction Ratios


Yildiz B., KÖKEN M. , GÖĞÜŞ M.

35th World Congress of the International-Association-for-Hydro-Environment-Engineering-and-Research (IAHR), Chengdu, China, 8 - 13 September 2013, pp.3966-3975 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Chengdu
  • Country: China
  • Page Numbers: pp.3966-3975

Abstract

This study deals with the temporal variation of scour around spill through bridge abutments at clear water conditions. Two spill through bridge abutments are connected at opposite sides of the sediment storage part of a rectangular channel which has a length of 29 m and a width of 1.5 m. Development of the scour is measured continuously at different cross sections around the abutment during experiments that lasted for 8 hours. These measurements are taken using an ultrasonic ranging system. Besides these continuous measurements the bathymetry around the abutment is obtained at three different time instants during the experiments. Using this bathymetry data, total scour volume is calculated at different time instants. These experiments are repeated for six different abutment lengths to see the effect of contraction ratio on the scour hole development. For the smallest contraction ratio, it was observed that a regular single sloped scour hole is forming at the initial stages of the scour which then turned into a form which consisted of a two leveled shape. The position of the maximum scour depth around the abutment is observed at the same place throughout the whole experiment both for the smallest and largest contraction ratios.