Reservoir dam erosion caused by an increased seepage velocity on downstream slopes is a major concern, and zoned-type dams are commonly used to mitigate this issue. However, previous methods for calculating filter spacing have been overly conservative, focusing on short-term stability and neglecting long-term erosion risk. This study proposes a determining equation for the horizontal filter spacing in reservoir dams, considering material property variability and diverse dam construction conditions. Through comprehensive three-dimensional seepage simulations, the lateral drainage range (LDR) and hydraulic gradient were investigated as separate factors. The proposed equation aims to optimize the filter design while balancing the safety and cost considerations. Validation using a multi-horizontal filter model confirmed the effectiveness of the proposed spacing in mitigating erosion hazards. This study contributes to the improvement in dam design practices by providing a less conservative approach. These findings offer valuable insights for designing horizontal filters in reservoir dams, ensuring both short- and long-term erosion stability. Ultimately, these advancements in filter design will enhance dam stability and reduce the risk of failure.

下游斜坡渗流速度增加引起的水库大坝侵蚀是一个主要问题，通常使用分区型水坝来缓解这一问题。然而，以往计算过滤器间距的方法过于保守，注重短期稳定性，忽视长期侵蚀风险。本研究提出了水库大坝水平过滤间距的确定方程，考虑了材料特性的可变性和不同的大坝建设条件。通过全面的三维渗流模拟，将侧向排水范围（LDR）和水力梯度作为单独的因素进行研究。所提出的方程旨在优化滤波器设计，同时平衡安全性和成本考虑。使用多水平过滤模型的验证证实了所提出的间距在减轻侵蚀危害方面的有效性。这项研究通过提供一种不太保守的方法，有助于改进大坝设计实践。这些发现为水库大坝水平过滤器的设计提供了宝贵的见解，确保了短期和长期的侵蚀稳定性。最终，过滤器设计的这些进步将增强大坝的稳定性并降低失败的风险。