六垛南闸闸下淤积加重原因及防淤减淤策略分析

Siltation Analysis and Dredging Strategy for Liuduo South Sluice

江苏灌溉总渠六垛南闸近年来闸下河道淤积明显加重,通过实测资料分析近年来灌溉总渠水沙条件变化特征及闸下淤积加重的原因,认为潮波变形引起的河口不平衡输沙是闸下淤积的根本成因,近年来上游来水减少及河口侵蚀加剧是闸下淤积加重的主要原因。进而总结了潮汐河口闸下淤积的机理和关键控制因素,并结合挡潮闸冲淤调度实践,提出了六垛南闸闸下清淤的策略和措施,认为下泄流量对闸下河道冲淤平衡起着决定性作用,水力冲淤辅助机械扰动可以大幅提升清淤效率,可作为六垛南闸清淤的常规措施。

In recent years,the sedimentation of Liuduo South Sluice of Jiangsu Irrigation Canal has been significantly aggravated.Based on the measured data,the variation characteristics of water and sediment conditions in the irrigation canal and the reasons for the aggravation of sedimentation under the sluice in recent years are analyzed,and the mechanism and key control factors of sedimentation under the sluice in tidal estuary are summarized.It is pointed out that the unbalanced sediment transport in the estuary caused by tidal wave deformation is the fundamental cause of sedimentation under the sluice,and the decrease of upstream water and the intensification of erosion in the estuary in recent years are the main causes of sedimentation under the sluice.Combined with the practice of scouring and silting scheduling of tidal gate,the strategies and measures of dredging under Liuduo South Sluice are put forward.The results show that the discharge flow plays a decisive role in the balance of erosion and deposition under the sluice.Hydraulic erosion and deposition assisted mechanical disturbance can greatly improve the efficiency of dredging,which can be used as the main measure of dredging in Liuduo South Sluice.