A Laboratory Study On The Erosion Properties Of The Tidal Flat With Bioturbation In Yellow River Estuary

Coastal erosion has gradually become a threat to marine life and living environment. Severe coastal erosion is in the Yellow River Delta. There are plenty of species in the tidal, and the bioturbation impacts on the sediments'physical and mechanical properties, such as changing the composition of the sediment and surface roughness; also they will affect the micro-topography and drainage condition. As a result, the anti-corrosion properties of the sediments also changed. For most areas from large-scale study of the erosion in the Yellow River Delta, there are a few studies from the biological perspective. Because of the complexity of biological processes, disturbance of the sediment consolidation of stability is to strengthen or weakened still controversial. The paper through laboratory tests to study the biological disturbance of tidal flat sediment erosion.In this paper, it is including indoor simulated waves under the Yellow River Estuary sediment soil column testing, by simulating a disturbance of caves and cave without disturbance of soil samples in response to the wave action. Monitor of soil in the pore water pressure changes with time, and analysis of biological experiments in caves on the two soil disturbance of the physical nature and mechanics of the impact and the reasons for the use of undisturbed soil samples. Test soil-erosion of soil samples and test pilot collapse. The biological disturbance of the cave sediments of the impact of erosion and soil samples with both the physical and mechanical indicators for further analysis of the reasons for this outcome.In this paper, draw the following conclusions:1 The existence of holes in the sediment makes the moisture content increase, the loose structure of the surface sediments, fine particle concentration increased, the upper cave soil strength decreases, the lower part of soil strength enhancement;2 Soil column testing, because of the existence of holes, the response of the external surface of soil to cyclic loading relatively sensitive. The performance of the mock cave soil surface pore pressure of the biological changes in rates is higher than non-simulated caves of the earth. Biological caves increase the permeability of the soils; reduce the soil pore water pressure accumulated.3 Soil samples from the status quo and soil-erosion of the soil samples can be seen in the pilot, a biological disturbance of the soil samples of anti-erosion to less than non-biological disturbance of the soil samples, and Two soil samples test of the anti-erosion generally become: When scouring velocity greater than the soil samples of sediment starting velocity, a kind of disturbed soil with no disturbance of the soil samples anti-erosion coefficient with the increased flow rate decreases, soil samples more easily be washed away, and no disturbance of holes in the soil samples of scouring caves factor greater than a biological disturbance of soil samples; But when the flow rate reached just starting velocity or flow large enough, there were small difference between holes in disturbance of soil samples and without disturbance of soil samples.4 The sediment bioturbation change the distribution of small particles and particles start critical condition, strengthened the flow of sediments, and accelerate the influx of beach erosion transport, making tidal flats of the plot of erosion increased.