Determination of scour depth of side weir in live bed river with genetic expression programming

Side weirs are hydraulic structures used for purposes such as controlling water height, discharging of waste water in the system and flow measurement and generally built on rivers. The most common hydraulic problems in live-bed streams are the problem of scouring. Local scour may cause damage and destruction of the bridge piers, side weirs or water dams. The data obtained in laboratory conditions or in the model environment can be used to understand the hydraulic factors of the local scour. Studies investigating the scour around side weir on the live-bed river is available in the literature. However, the methods in these studies are generally considered as experimental studies on the physical model. In the literature, the number of studies researching the scour depth on the mathematical model is limited. In this study, the scour depths around the side weir in the live-bed river were modeled mathematically using Gene Expression Programming. In our model, clear water scour and live-bed scour experimental data obtained in the live-bed linear channel were used. In this thesis, unattached non-dimensioned variables are formed while creating models; relative flow velocity (V/Vcr), dimensionless side weir length (L/b), relative side weir crest height ((h1-p)/h1) and bed material grain diameter (d50/p) using output data relative equilibrium scour depth (Hd/p). Formulations and expression trees of Model-1, Model-2 and Model-3 from 8 GEP models were presented in the study and the results of other models were given. As a result of the study, the values calculated in the mathematical modeling and the values measured in the physical model were determined to show a good performance and the scour depths around the side weir could be determined by using Gene Expression Programming in the live-bed rivers.