Performances of Straight Head and T-head Groynes as River Training Structures

Abstract

Any structure which is constructed within a river, for managing the flow of the river to make it beneficial for mankind is termed as river training structure. Groyne is one such type of hydraulic structures, which is generally constructed for various purposes including bank erosion prevention, facilitating smooth navigation, etc. These structures are generally constructed from the river bank and extend towards the main channel flow. Depending upon the head shape, groynes may be further classified into straight and T-head types. Literature survey has revealed that comparative analysis of performances of straight head and T-head groynes is still not sufficient enough. Therefore, in the present work numerical models have been developed for both the types of groynes specifically in channel bend and their performances are compared. In order to numerically simulate the flow processes, MIKE21C modeling tool is used here. From the comparison it appears that in case of T-head groyne, the shifting of the thalweg line from the outer is more. Moreover, higher value of sediment deposition is also observed in the T-head groyne field. All these results finally establish that T-head groynes are better than straight head groyne in river bend.