Many coastal engineering designs utilize empirical formulas containing the Equivalent Deep-water Wave Height (EDWH), which is normally given a priori. However, no studies have explicitly discussed a method for determining the EDWH and the resulting design wave heights (DEWH) under irregular wave conditions. Unfortunately, it has been the case in many design practices that the EDWH is incorrectly estimated by dividing the Shallow-water Wave Height (SWH) at the structural position with its corresponding shoaling coefficient of regular wave. The present study reexamines the relationship between the Shallow-water Wave Height (SWH) at the structural position and its corresponding EDWH. Then, a new procedure is proposed to facilitate the correct estimation of EDWH. In this procedure, the EDWH and DEWH are determined differently according to the wave propagation model used to estimate the SWH. For this, Goda's original method for nonlinear irregular wave deformation is extended to produce values for linear shoaling. Finally, exemplary calculations are performed to assess the possible errors caused by a misuse of the wave height calculation procedure. The relative errors with respect to the correct values could exceed 20%, potentially leading to a significant under-design of coastal or harbor structures in some cases.

许多沿海工程设计利用包含等效深水波高（EDWH）的经验公式，通常先验给出。但是，尚无研究明确讨论在不规则波浪条件下确定EDWH及其结果设计波高（DEWH）的方法。不幸的是，在许多设计实践中，都是通过将结构位置的浅水波高（SWH）除以其相应的规则波浅滩系数来错误地估计EDWH。本研究重新审查了结构位置处的浅水波高度（SWH）与其对应的EDWH之间的关系。然后，提出了一种新的程序来促进对EDWH的正确估计。在此过程中，根据用于估计SWH的波传播模型，以不同方式确定EDWH和DEWH。为此，哥达 扩展了非线性不规则波变形的原始方法，以产生用于线性浅滩分析的值。最后，执行示例性计算以评估由于错误使用波高计算程序而导致的可能误差。正确值的相对误差可能超过20％，在某些情况下可能导致沿海或港口结构的严重设计不足。