Grade control structures (GCSs) are common river training structures constructed to prevent riverbed degradation. Existing scour predictors for GCSs are based on flume experiments with either no sediment supply or equilibrium sediment transport conditions, the quantitative impacts of sediment supply on the scour at submerged GCSs are still unclear. The present study reports a series of flume experiments to investigate the effects of sediment supply on scour at submerged GCSs. The experimental results show that, compared with the equilibrium sediment transport condition, a decrease of upstream sediment supply rate can reduce the upstream scour depth (down to zero), increase the downstream scour depth (maximumly by 2.3 times) and change the scour process at a submerged GCS. If the sediment supply rate is close to the sediment transport capacity of the flow, the downstream scour depth first increases rapidly and then oscillates obviously around an equilibrium value (i.e. quasi-live-bed scour). If the sediment supply rate is close to zero, the downstream scour depth oscillates initially, then increases monotonically with time towards an equilibrium value (i.e. quasi-clear-water scour). Based on the experimental data and theoretical analysis, the quantitative impacts of sediment supply rate on the equilibrium scour depth at submerged GCSs are evaluated; and calculation methods considering the sediment supply are proposed for estimating the equilibrium scour depth at submerged GCSs.

坡度控制结构 (GCS) 是为防止河床退化而建造的常见河流治理结构。现有的 GCS 冲刷预测器基于没有沉积物供应或平衡沉积物传输条件的水槽实验，沉积物供应对淹没 GCS 冲刷的定量影响仍不清楚。本研究报告了一系列水槽实验，以研究沉积物供应对淹没 GCS 冲刷的影响。试验结果表明，与平衡输沙条件相比，上游输沙速率的降低可以降低上游冲刷深度（降至零），增加下游冲刷深度（最大2.3倍），改变冲刷过程一个淹没的地面站。如果输沙率接近水流输沙能力，下游冲刷深度先快速增加，然后在平衡值附近明显震荡（即准活床冲刷）。如果泥沙供应率接近于零，下游冲刷深度最初会振荡，然后随时间单调增加至平衡值（即准清水冲刷）。基于实验数据和理论分析，评估了输沙率对淹没 GCS 平衡冲刷深度的定量影响；并提出了考虑沉积物供应的计算方法，用于估算淹没 GCS 的平衡冲刷深度。准活床冲刷）。如果泥沙供应率接近于零，下游冲刷深度最初会振荡，然后随时间单调增加至平衡值（即准清水冲刷）。基于实验数据和理论分析，评估了输沙率对淹没 GCS 平衡冲刷深度的定量影响；并提出了考虑沉积物供应的计算方法，用于估算淹没 GCS 的平衡冲刷深度。准活床冲刷）。如果泥沙供应率接近于零，下游冲刷深度最初会振荡，然后随时间单调增加至平衡值（即准清水冲刷）。基于实验数据和理论分析，评估了输沙率对淹没 GCS 平衡冲刷深度的定量影响；并提出了考虑沉积物供应的计算方法，用于估算淹没 GCS 的平衡冲刷深度。评估了沉积物供应率对淹没 GCS 平衡冲刷深度的定量影响；并提出了考虑沉积物供应的计算方法，用于估算淹没 GCS 的平衡冲刷深度。评估了沉积物供应率对淹没 GCS 平衡冲刷深度的定量影响；并提出了考虑沉积物供应的计算方法，用于估算淹没 GCS 的平衡冲刷深度。