Simulating geobag revetment failure processes

An experimental and numerical study has been carried out to help develop design guidelines for the construction of low-cost river bank protection using geobags. Building upon previous work, a 1:10 scale model was tested in a laboratory flume, comparing two different construction methods (running bond and stack bond), subjected to three different water depths. It was found that whilst the failure pattern was highly dependent on water depth, the construction method had no noticeable impact, and it was concluded that the dominating factor is the friction between individual geobags, which itself is dependent on bag overlap rather than specific construction method. A simple Discrete Element Method (DEM) model was constructed using the LIGGGHTS open source software with drag and lift models applied to a multi sphere simulation of the laboratory model geobags. It was found that despite its simplicity this DEM model could reproduce the failure pattern of revetments very well, and thus has potential for future use in developing design guidelines aimed at the developing world.