【摘要】 钱塘江涌潮在低潮位时的大流速具有很大的挟沙能力,会淘刷海塘基础前的近塘滩地,降低海塘建筑物的稳定性,甚至损毁堤塘.护塘低丁坝群可改变涌潮传播规律,分散涌潮对建筑物的作用力,从而减轻近塘滩地淘刷,提高海塘的整体和局部稳定性.传统的堆石丁坝由于基础较浅,且以散抛块石为基础,处低潮位时在涌潮动力持续打击、猛烈震动作用下易招致丁坝损毁破坏.本文提出了一种新颖的丁坝型式,并从现场观测资料分析、实体模型试验和机理分析三个方面,分析桩式丁坝的护滩保塘效果,并从潮流过坝的水力特性角度,探究丁坝护塘的机理.与传统的堆石丁坝比较,桩式丁坝具有设计合理、施工简易、坝体内无内压力、便于维护检修等一系列优点.可广泛应用于各类河道整治、海塘保护等工程中.更多还原

【Abstract】 Great velocity of Qiantang bore has immense silt-carrying capacity at low tidal level.It can undercut flat near dyke,reduce the stability of seadyke and destroy sea dyke.The Low sheet-pile groins can change the spread law of bore,decentralize the acting force of bore on hydraulic structure.Consequently scouring of tidal flat near dyke will be alleviated with sheet-pile groins and and integral and local stability of sea dyke will be improved.However,as the base of traditional riprap groins is shallow and take dispersed blocks as the base. Under continuous beating and shock of power of tidal bore,riprap groins lead to damage or destroy when at low tidal level.A new type of groin is introduced.From the start of on-site observations,physical model experiment and mechanism analysis,the effect of flat-maintenance and dyke-protection of sheet-pile groins is analysed.From hydraulic characteristics of tidal flow over groins,the mechanism of flat-maintenance and dyke-protection of sheet-pile groins is discussed.Contrast to traditional riprap groins,sheet-pile groins is characterised by rational design,simple construction and convenient for maintenace and service,no inner pressure in groin body and so on.Sheet-pile groins may be extensively applied to all river training and sea-dyke protection.更多还原