中文摘要：

海堤在风暴潮和极端波浪的联合作用下极易发生堤顶大量越浪，而越浪量的增加可能导致防波堤后坡的破坏，造成重大生命财产损失。针对这一问题，对防波堤后坡抛石护面进行系列二维物理模型试验，根据越浪对堤后不同抛石重量的冲刷破坏情况，将抛石重量换算为厚度后，讨论堤后抛石稳定厚度与越浪量之间的关系。结果表明，稳定厚度与越浪量成线性相关。为便于公式直接应用于实际工程中，对平均越浪量进行分析，并对比国内外现有越浪量计算公式，结合我国常用防波堤结构形式，提出不规则波作用下的平均越浪量计算公式。最终给出不规则波作用下后坡抛石稳定重量的计算公式，可为我国防波堤后坡护面结构设计提供重要参考依据。

英文摘要：

Overtopping will occur under the combination of wave and storm surge. Dike failure caused by overtopping breakwater will result in a serious loss of lives and property. To solve this problem, a series of 2D physical model tests were conducted on the stable thickness of riprap on the inner slope of the breakwater. According to the erosion of riprap with different thicknesses, further discussion of the relationship between armor thickness and average overtopping is made.Equations are given for stable thickness of facing block on the inner slope. New equations are also presented for average overtopping discharge based upon the analysis of mean wave overtopping and comparison of the domestic and foreign existing overtopping formulas. It may provide important reference for design of breakwaters and seawalls.