Comparative analysis of effectiveness of I Head, L Head and T Head Groyne

In the present scenario of changing hydrological patterns due to natural and human-induced reasons, the need for effective management of the river system has become more pronounced than ever. This emphasises the necessity to construct river training structures to mitigate the effect of floods and riverbank erosion. Groynes are river training structures provided to protect and stabilise the riverbanks. Most of the previous studies on these structures focused on studying the flow pattern around I Head groyne in the sand bed. Limited research has been done on L Head Groyne (LHG) and T Head Groyne (THG). This study compares bed morphology and flow pattern around three types of groyne: IHG, LHG, and THG in gravel bed. Experiments were conducted to study and compare the flow characteristics around these groynes under similar flow conditions. The flow depth was maintained at 0.136 m, and the Froude number was kept at 0.61. The maximum scour depth observed for LHG and THG is around 38 % more than that of IHG. The normalized velocity distribution is also compared for the three. It is observed that the reduction in streamwise velocity is maximum for the LHG. The study offers insights into the bank protection capability of the three types of groynes and distinguishes the role of these structures in achieving the different objectives of rivertraining works.