Author(s): M. W. Morris; M. A. A. M. Hassan; G. Ghataora; P. G. Samuels
Linked Author(s): M.W. Morris
Keywords: No Keywords
Abstract: Accurate numerical modelling of breach formation through embankment dams or flood embankments presents a difficult challenge since the breaching process entails complex interactions between flow, soil and structure. Different breach formation processes occur with different materials and material states; researchers have also taken a range of different approaches, producing simple equations and 1D, 2D or even 3D numerical models in attempts to provide a reliable means for predicting breach formation. In recent years there have been a series of projects which have provided a platform for fundamental research and the basis for development of new or improved numerical models. In particular, work under the IMPACT project (www. impact-project. net) provided data such as flow rates and velocities, water levels and video footage for five large scale field tests, and a further 22 supporting (1:10 scale) laboratory tests (Morris et al. 2007). This paper introduces the analysis of this unique video footage and highlights key physical processes that occurred during the tests. These processes included 3D flow processes, embankment surface erosion, head cut formation and soil wasting (through discrete side slope failures). The analysis also shows that understanding soil state is a common issue when considering all of these processes. The relevance of these processes for more accurate breach modelling is then considered, and conclusions, with examples, provided.
Year: 2009