长江三角洲前缘的典型平原感潮河网地区，河道水系密布、通航频繁，堤防工程的安全受航道运行、泥面冲刷影响较大。为研究通航感潮河道堤防结构抗冲敏感性及其变化规律，选取黄浦江上游某通航支流堤防实际运行条件计算出理论冲刷深度，并以该值为参考，通过有限元模型分析重力式堤防、桩基式堤防在不同结构尺度与冲刷深度耦合下的位移响应，得到不同堤防结构型式的抗冲敏感性及变化趋势。研究结果表明：重力式堤防的抗冲敏感性主要受底板宽度和埋置深度影响，当底板宽度<4.0 m或埋置深度<2.0 m时，墙前冲刷0.5~1.0 m即出现墙顶位移速率陡增；当底板宽度>5.0 m或埋置深度>2.0 m后，继续增大尺度对抗冲性能的增益显著降低。桩基式堤防的抗冲敏感性主要受桩基长度控制，当桩基长度<15.0 m时，冲刷1.0~1.5 m后位移增长速率明显加快；桩基长度>15.0 m后，增加桩基长度对提高抗冲性能的效果减弱。根据研究结果提出堤防结构抗冲经济尺度，并确定不同冲刷条件下的结构适应性，为通航感潮河道堤防结构设计和管理提供科学依据。

[Objective] In typical plain tidal river networks at the Yangtze River Delta front， dense waterways and frequent navigation significantly impact levee safety through channel operations and bed scour. Focusing on two typical levee structural types along the Huangpu River and its main tributaries， this study investigates the scour response under the coupling of structural dimensions and scour depth. The findings aim to provide a scientific basis for accurately identifying high-risk bank sections， optimizing bank protection structures， and enhancing the targeted management of levee engineering in tidal navigable rivers. [Methods] To examine the scour resistance sensitivity and its variation of levee structures in tidal navigable rivers， the theoretical scour depth was calculated based on the actual operating conditions of a navigable tributary in the upper Huangpu River. Using these calculated values as a reference， finite element models were developed to analyze the displacement responses of gravity-type and pile-founded levees under coupled conditions of varying structural dimensions and scour depths. This approach allowed for the determination of the scour resistance sensitivity and evolutionary trends for different levee structural types. [Results] The scour resistance sensitivity of gravity-type levees is primarily influenced by the base slab width and embedment depth. When the base slab width is <4 m or the embedment depth is <2 m， a toe scour 0.5-1.0 m triggers a sharp increase in the displacement rate at the wall top. Conversely， when the base slab width exceeds 5 m or the embedment depth exceeds 2 m， further increasing the dimensions yields significantly diminishing returns in scour resistance. The scour resistance sensitivity of pile-founded levees is mainly governed by the pile length. When the pile length is <15 m， the displacement growth rate accelerates markedly once the scour depth 1.0-1.5 m. Beyond a pile length of 15 m， the effectiveness of increasing pile length to enhance scour resistance weakens. [Conclusion] （1）The sensitivity of different structural types to toe scour must be fully considered during the selection and sizing of levee structures in tidal navigable rivers. Under the given typical boundary conditions， the scour resistance sensitivity increases with the base slab width， embedment depth， and pile length. However， beyond certain thresholds， the marginal gain in sensitivity decreases， making it economically inefficient to further improve scour resistance solely by enlarging structural dimensions. Instead， altering the structural type or controlling the scour depth is recommended to enhance levee safety. （2）For the design of gravity-type levees， it is advisable to maintain a base slab width of ≥4 m and an embedment depth of ≥3 m. If the anticipated scour depth exceeds 1 m， gravity-type structures are not recommended. For existing gravity levees， the impact of scour should be mitigated through strengthened vessel traffic management and the installation of protective structures. （3）For the design of pile-founded levees， the pile length should be controlled at ≥15 m. When the anticipated scour depth reaches 1 m， measures such as enhanced vessel traffic management and protective structures should be implemented to reduce scour impacts. The proposed structural dimensions and structural adaptability under varying scour conditions provide a scientific basis for the design and management of levees in tidal navigable rivers.