COMPARATIVE EVALUATION OF SCOUR AROUND I, L, AND T SPURS ON GRAVEL BED

Abstract

Groynes are frequently used to preserve eroding riverbanks and change the flow direction in channels. Groynes are better than other bank protection structures and helpful for aquatic habitat resources. Due to the constriction of the flow area, local velocity changes and scouring around the groynes is formed. In order to guarantee the safety of such groynes for riverbank protection, it is necessary to understand the features of near-bed turbulence. This research study entails a comparative analysis of the scour depth in the vicinity of straight, L-head, and T-head groynes, while considering various flow parameters such as time-averaged three-dimensional velocity distribution, Reynolds stresses, and bed shear stresses associated with each groyne type. The investigation is conducted within a channel characterised by a Reynolds number of 9.6 x 104 and a Froude number of 0.614. The measurement of scour depth is performed utilizing a vernier point gauge, allowing for a comprehensive assessment of scour variations across different groyne shapes. Furthermore, the maximum scour depth is determined and, revealing that L-head groynes exhibit the most substantial scour depth. To quantify the extent of scour and deposition, the PYTHON programming language is employed to calculate the respective volumes associated with each groyne type.