Thesis Type: Doctorate
Institution Of The Thesis: Gazi University, Turkey
Approval Date: 2016
Thesis Language: Turkish
Student: Onur Karakurt
Supervisor: MÜSTEYDE BADUNA KOÇYİĞİT
Abstract:During flooding, sudden and substantial increase in water level and discharge of rivers occurs and this in return may substantially affect scouring around bridge piers causing severe damage and even collapse of bridges. In this study, a series of experiments in a flume was conducted to investigate the shape and depth of the scour hole occurred on the base of the flume underneath a bridge deck that was subject to pressurized and weir type of flows under clear water conditions and to examine the effect of various parameters on the scour hole. In the experiments, parameters of flow, sediment and geometric features of the bridge that were considered to have effect on maximum scour hole depth were taken into consideration. Approach flow depth, discharge, girder depth, sediment size, position of bridge deck and girders are among those parameters whose effects on score hole depth for both pressurized and weir flow types were investigated separately. Two empirical equations were developed for both pressurized and weir flow types by using regression analysis of the measured data. It was observed that fine sediment, deck's location with respect to flume bed, and smaller depth of approach flow at constant discharge increase the depth of maximum scour hole. Furthermore the effect of flow type on the scour hole was examined at the same approach flow and it was found out that there was serious increase in the maximum scour hole depth under pressurized flow conditions.