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In order to examine the effectiveness of engineering protection against localized scour in frontof the south groin-group of the Yangtze Estuary Waterway Improvement Project,Phase I,an undistort-ed physical model on a geometric scale of 1:250 is built in this study,covering two groins and their adacentestuarine areas.By use of rinsing fix-bed model as well as localized mobile-bed model,the experiment isundertaken under bi-directional steady flow.According to the experimental results,waterway dredgingleads to the increase in steram velocity,the increase being larger during the ebb than during the flood.Con-struction of the upstream groin has some influence on the flow patterns near the downstream groin.Local-ized scour in front of the groin-heads is controlled mainly by ebb flow.In the case of a riverbed composedentirely of silt,the depths of localized scour in front of the two groin-heads are 27 m and 29 m,respectively.In reality,the underneath sediment of the prototype riverbed is clay whose threshold ve
In order to examine the effectiveness of engineering protection against localized scour in front of the south groin-group of the Yangtze Estuary Waterway Improvement Project, Phase I, an undistort-ed physical model on a geometric scale of 1: 250 is built in this study, covering two groins and their adacentestuarine areas. By use of rinsing fix-bed model as well as localized mobile-bed model, the experiment is undertaken under bi-directional steady flow. According to the experimental results, waterway dredgingleads to the increase in steram velocity, the increase being larger during the ebb than during the flood. Conftruction of the upstream groin has some influence on the flow patterns near the downstream groin. Local-ized scour in front of the groin-heads is controlled mainly by ebb flow. the case of a riverbed compose dentirely of silt, the depths of localized scour in front of the two groin-heads are 27 m and 29 m, respectively. reality, the underneath sediment of the prototype riverbed is clay whose threshold ve