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在淤泥质河口、海岸地区,港池和航道开挖后,挖槽内外经历着冲淤交替过程,在挖槽中由于水流作用的弱化,使得槽内淤积增加而冲刷减少,并随槽内深度增加而产生净淤积(即回淤)。挖槽回淤的沉积动力学途径,是建立在对冲淤机理分析和冲淤过程的合理概化基础上,可以构造半经验的回淤预报公式,也可为冲淤数学模型提供合理的结构和参数,关键是采用水动力强度指标,即水流及波浪引起的底部切应力τ(或摩阻流U)来界定冲淤发生的条件和衡量冲淤发生的规模;此外还必需分析和表达挖槽工程区域水体含沙量的时空分布;工程区沉积物的平面及柱状分布及其物理力学指标、沉速、淤积切力、冲刷切力、固结过程、流变参数等的实验测定。
After the excavation of the muddy estuaries, coastal areas, harbor pits and waterways, the process of erosion and deposition alternated inside and outside the excavation tank. Due to the weakening of water flow in the excavation tank, siltation in the tank increased and scouring decreased, and with the depth of the tank Increase and produce a net siltation (ie back silting). The dredging sedimentation kinetics is based on the reasonable generalization of scouring silting mechanism and scouring and silting process. The semi-empirical silting forecasting formula can be constructed, and the mathematical model of scour silting can be provided with reasonable structure and Parameters, the key is the use of hydrodynamic strength indicators, that is, flow and wave caused by the bottom shear stress τ (or friction flow U) to define the conditions of scour and silting and scouring and silting occurs in the scale; also must analyze and express the trenching The spatial and temporal distribution of sediment concentration in the project area; the plane and columnar distribution of the sediment in the project area and its physical and mechanical indexes, sedimentation rate, sedimentation shear force, scouring and shear force, consolidation process and rheological parameters.