Open AccessExperimental study for determination of collar dimensions around bridge pier
Author(s) -
Afshin Jahangirzadeh,
Shatirah Akib
Publication year - 2015
Publication title -
the baltic journal of road and bridge engineering
Language(s) - English
Resource type - Journals
eISSN - 1822-4288
pISSN - 1822-427X
DOI - 10.3846/bjrbe.2015.11
Subject(s) - pier , collar , flume , structural engineering , geotechnical engineering , bridge scour , current (fluid) , engineering , geology , mathematics , geometry , flow (mathematics) , electrical engineering
The shape and size of a collar is important to maximize its effect as a scour countermeasure. Current research shows that the depth of the scour hole is decreased by using rectangular collars around circular piers. This study determined the approximate optimum dimensions for rectangular collars to minimize the temporal trend of scouring around a pier model. Effects of different sizes of rectangular collars on a model pier were investigated both at the upstream and downstream of the flume. It was observed that irrespective of the rectangular collar dimensions the upstream and the downstream were estimated to be 0.86 and 1.42, respectively. The optimum collar width was estimated to be 2.8 times the diameter of the pier. By using this optimized collar dimension, the non-dimensional depth of scour reached a min value of 0.034 at 72 h. The reduction percentage of the scour depth reached 98% at 72 h.