Numerical study on the disposal of barged sediments
Voong, Jing Kai
Date of Issue2017-12-21
School of Civil and Environmental Engineering
Barge sediment disposal in open water often requires water quality impact assessment by the regulatory agencies prior to the approval of disposal. Existing model such as STFATE (Short Term Fate Model) is commonly used in the industry to simulate the short-term fate of the sediments upon releasing into the water. However, STFATE assumes that sediments are released from an axisymmetric point source and models the release as a series of three-dimensional clouds with different insertion speeds. This assumption provides a fast analysis but it does not represent the actual physical conditions of the released sediments, which are usually carried out and disposed through barges (Er 2017). Experimental data shows that the classification scheme in BSDM (Barge Sediment Disposal Model) would better represent the dynamics of sediment cloud from a barge disposal. In the present study, literature review was conducted to explore the cases of field sediment disposal that were reported in the past and attempted to simulate them with BSDM, in order to validate and improved BSDM. In some cases, sediment clumps were reported, which was not initially considered in BSDM. They found were found to weaken the propagation of bottom surge due to the immediate deposition upon impact, and reduced the amount of sediments that contributed to the bottom surge. Experiments were carried out to quantify the effects of sediment clumps on the bottom surge. Cases with sediment clumps reported were re-simlated by taking into account the experimental findings. The re-simulated results showed improvement in predicting the dynamics of bottom surge.
Final Year Project (FYP)
Nanyang Technological University