After construction of BRIDGE pier in a river, a 3D complex flow pattern forms around PIERS and erosion of bed material occurs and if foundation depth or piles depth was not sufficient, the BRIDGE will be collapsed. One of devices to reduction of scour around BRIDGE PIERS is an installation of sill beside of PIERS. In this research, effect of sill on reduction of scour around the INCLINED BRIDGEs PIERS GROUP under various hydraulic condition and top level of installation of foundation was investigated experimentally. The model of BRIDGE pier was 1.190 scaled of 8th BRIDGEs of Ahvaz, Iran, which had INCLINED rectangular of 2.5 cm length and 3.5 cm width and was placed on the foundation of 10 cm width and 16 cm of length with inclination of 28 degree. Experiments was conducted for different location of sill (front, middle and downstream) of foundation which installed at relative level, height of top of foundation to width of it, -1, -0.5, 0 and 1. Comparison of results showed that installation of sill in front of foundation had the best performance to decrease of scour depth. Furthermore, the reduction of scour depth as the top level of foundation was placed at same level of bed, was considerable.

Advancement of technology in construction of structure caused to design modern type of BRIDGE PIERS including INCLINED BRIDGE PIERS GROUP. Due to importance of identifying effective mechanisms of scour around this type of BRIDGE PIERS, in this research the effect of flow parameter and level of BRIDGE foundation on the scour depth was investigated. BRIDGE PIERS GROUP included two INCLINED rectangular PIERS of 2.5cm width and 3.5cm length which installed at the angle of 28 degree on the top of rectangular foundation of 10cm width and 16cm length. Experiments were performed for various relative velocities, depth of flow and relative top level of the foundation from the channel bed (Z/D*) -1 up to 1. The results showed that the velocity of flow has more effect on the local scour depth in comparison of the flow depth. Comparison of results for different levels of the foundation showed that level of the foundation has significant effect on the scour depth. A maximum and a minimum scour occurred for relative foundation level 1 and -0.5. Furthermore, except of relative foundation -0.5, the scour at the INCLINED BRIDGE level is more than individual pier.

Background and Objectives: The main cause of collapse of BRIDGEs is scour around BRIDGE PIERS. Therefore, knowledge about the effective parameters and estimation of maximum scour depth has an important role on the safe design of BRIDGEs in rivers. The aim of this research is evaluation of optimized ANFIS parameters with GA on prediction of maximum scour depth and comparison with all FIS generator of Matlab Toolbox ANFIS.Materials and Methods: To evaluate prediction of scour depth around INCLINED BRIDGE PIERS located on rectangular foundation using optimized ANFIS parameters with GA and Matlab ANFIS, 48 sets of experimental data of scour around incline BRIDGE PIERS were used. To compare the performance of results, R2 and RMSE were utilized.Results: Analysis of results showed that GENFIS1 generator of ANFIS toolbox in Matlab had the best performance, which could predict maximum scour with R2 and RMSE, 0.976 and 0.053, respectively. Comparison of the predicted scour depths indicated that optimization of ANFIS parameters had better desired parameters prediction with R2 and RMSE, 0.992 and 0.02537 in comparison of ANFIS toolbox in Matlab.Conclusion: Comparison of results indicated that both ANFIS toolbox in Matlab and optimized ANFIS could predict desired output, but the study are encouraging and suggest that an optimized adaptive neuro-fuzzy approach is a powerful tool to model scour depth around INCLINED BRIDGE PIERS GROUP which could reduce RMSE from 0.053 to 0.0254.

Considering the importance of scouring in the design of BRIDGEs, nowadays, to increase the accuracy of scour depth estimation, artificial neural networks are used. In this research, a model for estimating scour depth around the BRIDGE pier GROUP was used by a new method called support vector machine. In this method, the statistical parameters of RMSE, R 2, DC, were used to evaluate the performance of the models. The results showed that using compounds of the sedimentary and hydraulic parameters in the support vector data model provided better results in estimation of scour depth. For example, in tripod mode, the assessment criteria values for the scenario 1 (hydraulic parameters), were R 2 = 0. 9914, DC = 0. 9758 and RMSE= 0. 0576, and for scenario two (hydraulic and sediment parameters), were to R 2 = 0. 9924, DC = 0. 9803 and RMSE = 0. 0529, which indicated better performance of the support vector machine in the second scenario. Finally, non-linear equations were presented for calculating the scour depth around the INCLINED Single and GROUP PIERS.

Ripraps are placed around BRIDGE PIERS to prevent scour and secure the PIERS from failure. Proper riprap cover is essential to be economical. The present study examines using of riprap for reduction of local scour in PIERS GROUP and the results are compared with data from riprap on a single pier. The models consist of two and three circular-shaped PIERS in line with the flow, with the diameter of 0.02 m and pier spacing of twice and four times the pier diameter. Four uniform riprap sizes with the diameters of 2.86, 3.67, 4.38 and 5.18 mm were used to cover the PIERS. The results showed that the effect of wake vortices formed at the downstream side of PIERS GROUP was decreased as compared with single pier. The reinforcing and sheltering effects caused 31% decrease in front pier and 60% increase in back pier, respectively, for the length of cover riprap. The reinforcing and sheltering effects were decreased by increasing pier spacing, but the riprap pattern was not affected. In triple PIERS GROUP, scour depth in the second pier was less than the first pier and in the third pier was less than the first and second PIERS. In double and triple PIERS GROUP, the sheltering effect reduced the scour depth (46% and 54%, respectively) in the back pier with respect to the single pier. Reduction of dimensions in scour hole of back pier in triple PIERS GROUP was 67% with respect to double PIERS GROUP, which is the result of sheltering effect of first and second PIERS. The best shape for the riprap was semi-oval. The riprap length in double and triple PIERS GROUP was reduced by 31% and 37.5%, respectively, as compared with the single pier.

After construction of BRIDGE pier in a river, eddy flow pattern forms around the PIERS and erosion of bed material and scouring occur, and if foundation depth or piles depth is insufficient, the BRIDGE will be collapsed. In this research, effects of the installation angles of PIERS GROUP on scour dimensions under different hydraulic conditions and top levels of foundation installation were investigated experimentally. The model of BRIDGE PIERS GROUP was placed on a rectangular foundation with 3 angles of installation (vertical, degrees of 28, 38 and 45). Experiments were conducted under two different relative velocities (ratio of flow velocity to corresponding inception of motion velocity, 0.8 and 0.95) and three relative levels of foundation (ratio of top level of foundation to width of it, zero, -0.5 and -1). Comparison of the results showed that at zero relative level of foundation, the top level of foundation played as collar and the minimum scour occurred at the vertical installation angle. At the other relative levels of foundation and among the different installation angles of the PIERS, the angles of 28 and 38 had the maximum and minimum scour depths respectively. Furthermore, variation of the maximum length of scour had a similar trend to the scour depth.

One of the vital structures in the land transportation cycle is the BRIDGE. Constructing this structure over the rivers results in an intensified 3-D flow pattern around PIERS which in turn causes the bed sediments to be eroded and scoured from the immediate vicinity of the pier and its foundation. It is likely that the BRIDGE will fail particularly during a high flood event, if the foundations or piles are not constructed deep enough. Hence, besides the previous works on the study of the factors affecting scour at BRIDGE PIERS, considering appropriate countermeasures against BRIDGE scour is of primary importance. In the present study, the effect of bed sill location on the temporal evolution of the scour around an INCLINED pier GROUP was experimentally investigated under various hydraulic conditions and foundation levels. A physical model of pier GROUP with two INCLINED 2.5 ´ 3.5 cm rectangular PIERS and 28 degree inclination angle constructed on a 10 ´ 16 cm foundation was considered in the experiments. The experiments were carried out with different locations of sill (front, middle, and rear of the foundation), various flow velocities and depths, and normalized installation levels of the foundation (distance of the top of the foundation to the bed surface normalized by the pier width) equal to -1.0, -0.5, 0.0, and +1.0. The results of the present study indicate that the bed sill location has a significant effect on the temporal evolution of the depth of scour hole. Based on the comparisons made in this study, it is found that the installation of the sill in front of the foundation has a better performance in the scour mitigation rather than other arrangements. It is also concluded that the average reduction in the scour depth in all foundation installation levels is equal to 22, 18, and 15 percent for front, middle, and rear sill configurations, respectively.

Introduction: BRIDGEs are certainly one of the most important structures but costly service elements in a transport system. The BRIDGEs are very required to access the damaged areas in emergency situations such as floods and earthquakes. Scour around the foundations of BRIDGE PIERS exposed to the flowing water than can destroy the BRIDGE itself is a subject of major concern. Flow pattern is known as responsible for all changes in stream bed. Any obstacle in the channel can form new flow patterns causing additional shear stress exerted on the bed than the equilibrium condition of the absence of the obstacle. Appropriate shaping of flow pattern and proper selecting of pier geometry and the location of BRIDGE PIERS can be one of the proper methods in reduction of scour amount which is the main subject of the present study.Materials and Methods: INCLINED BRIDGE GROUP pier is a type of BRIDGEs with modern geometry based on development in building technology of structures. Many of these BRIDGEs have been built all around the world and the 8th BRIDGE built crossing the Karun River in Ahvaz is a sample of the Iranian ones considered in this research. Hydrodynamic behavior of flow is investigated around the INCLINED BRIDGE GROUP pier settled on foundation using the FLOW-3D numerical model. INCLINED BRIDGE GROUP pier investigated in this study, includes two rectangular PIERS which are 2.5 cm long and 3.5 cm wide and set in an angle of 28 degree on rectangular foundation which is 16 cm long and 10 cm wide and installed in three different foundation levels namely at, above and below the bed levels. The physical model of prototype pier considered in this study was constructed to the scale of 1: 190 of the Ahvaz 8th BRIDGE. In order to verify the accuracy of the numerical model, velocity data obtained from image processing technique were used.

BRIDGEs are the most important structures in river engineering. One of the most causes in BRIDGEs destruction is local scouring around the BRIDGE PIERS. Many BRIDGEs failed in the world because of the extreme scour around PIERS, which have caused to disappear a lot of investments. Then, it is essential to predict the scour depth around BRIDGE PIERS. In this research, the Fluent three-dimensional numerical model was used to investigate the scouring around the GROUP cylindrical pier in clear water and uniform sand bed conditions. In this model, sedimentary flow was considered as two-phase flow (water - sand) and Eulerian two-phase model was used. To estimate the parameters of flow turbulence in the water phase, the RNG K-e model was used. To evaluate and verify the numerical model, the computational results were compared with experimental data. The maximum scour depth in front of the first pier on a numerical model equal to 12.5 cm and in experimental model equal to 12 cm have been measured. Also scour depth at the second pier less than that at the first pier and scour depth at the third pier has been less than the values of the first and second pier. The results showed that the two phase model can simulate the scour phenomena around the pier.