福姜沙水道双涧沙滩面越滩流对滩槽稳定的影响

Impact of Shuangjian shoal beach face's beach flow on beach-bath stability in Fujiang shoal reach

以福姜沙水道双涧沙为研究对象,通过原型观测资料分析和数学模型手段,分析双涧沙越滩流成因与分布规律,并探讨其对深水航道的影响。结果表明:落潮时受福北水道章春港以下过流能力逐步减弱的影响,进入福北水道的水流沿程逐步越过双涧沙滩面进入浏海沙水道,涨潮时浏海沙水道涨潮流逐步越过双涧沙进入福北水道。越滩流的大小和强度分布主要与上游来水、双涧沙沙体地形条件等有关——大水越滩流位置下移,小水越滩流位置上提。过大强度越滩流的存在不利于双涧沙滩面稳定,冲刷输移的泥沙不利于临近航道水深条件的维护。

Taking Shuangjian shoal in Fujiang shoal reach as a study case, we analyze the formation cause and distribution law of the beach flow of Shuangjian shoal by the prototype observation data analysis and mathematical model method, and probe into its impact on the deepwater channel.The results show that in the ebb tide, due to the gradual weakening of the flow capacity below Zhanchun port in Fubei channel, the flow entering Fubei channel crosses over Shuangjian shoal beach face gradually and enters Liuhai shoal reach; while in the flood tide, flow in Liuhai shoal reach crosses gradually over Shuangjian shoal beach and enters Fubei channel.The size and intensity distribution of the beach flow relates mainly to the upstream inflow and the terrain conditions of Shuangjian shoal beach, i. e., the beach flow moves downward in the floods and upwards in the low water.The beach flow with great intensity is unfavorable for Shuangjian shoal beach face′s stability, and the transported sediment due to scouring is disadvantageous for the maintenance of the adjacent channel depth condition.