Author(s): D. P. L. Ranasinghe; I. G. I. K. Kumara; N. L. Engiliyage; K. Raveenthiran
Linked Author(s): Prasanthi Ranasinghe
Keywords: Crest level; Dummy water levels; Physical models; Toe stability
Abstract: Physical models can save a substantial amount from the actual construction coat even though the procedure is cost and time consuming than the other design techniques. The objective of this study was to use the constructed physical model to represent the different toe and the crest levels by adjusting the water levels during the model testing. Application of dummy water levels for toe optimization has been adopted for the various 2D models done in Lanka Hydraulic institute Ltd (LHI) and the outcome of two of them are (shallow and deep water coastal structures) presented in this paper. The crest optimization has been done for a deep breakwater by changing the water levels to represent the effective freeboard for the overtopping. The same design waves were applied for different water levels as deep water wave conditions are not much varying at the adjacent water depths. Since the toe stability is assessed by considering maximum wave height that can be generated at the critical low water level, effective water depth at the toe has been considered while optimizing the toe elevation using adjusted water levels. This paper includes the discussion on toe stability for deep and shallow water sections as well as the suitability of dummy water levels for engineering judgments while optimizing the crest and toe levels of the coastal structures. The results concluded that the dummy water levels can be used as an alternative method for crest and toe level optimization instead of having structural modifications of the model.