长江中游界牌河段丁坝周围水流特性试验研究

Experiment on characteristics of flow around spur dike in Jiepai reach of middle reaches of the Yangtze River

为探求界牌河段丁坝周围水流特性,明晰丁坝周围水流特性与坝头损毁之间的关系,采用清水定床、正态模型试验方法研究长江界牌河段丁坝周围水流结构特点,详细分析流量条件对界牌7^(#)丁坝周围断面测点的流速最大区域及紊动强度最大区域分布的影响,重点分析坝头周围测点三维流速数据。结果表明,从x、z向流速和紊动强度的角度考虑,坝体中部及下游侧是易损区域;随着坝头流速的增大,下潜水流、坝头涡旋系、单宽流量分别成为影响坝头损毁的主因。

In order to explore the characteristics of flow around the spur dike in Jiepai reach and clarify the relationship between the flow characteristics and the damaged dike head,this paper,under clear water and fixed bed conditions,uses the normal model to study the characteristics of flow around the spur dike in Jiepai reach of the Yangtze River and analyzes the influence of flow conditions on distributions of areas with the maximum velocity and maximum turbulence intensity from measured sections around the spur dike in Jiepai reach,especially the three-dimensional velocity data measured around dike head.The results show that the middle and lower parts of the dike are vulnerable areas from perspectives of velocity and turbulence intensity in x and z directions.As the velocity in the dike head increases,the submerged flow,dike head vortex system,and unit discharge are the main factors damaging the dike head.