Abstract The analysis of damage in rubble mound scour protections is crucial for the armour stability assessment. Former methodologies focused on the analysis of the maximum damage number. This work introduces a complementary methodology to determine and characterize damage statistical distribution based on a flexible arrangement of sub-areas. The sub-areas are overlapping and can be varied in size, allowing a refined damage analysis. To capture the variation of damage with changing sub-area layout, the methodology is coupled with a statistical evaluation of damage numbers, which is enabled by the definition of a grid ratio between armour stone size and sub-area size, (Dn50)2/Asub. The methodology is applied to high resolution bathymetric surveys from two stability tests of large-scale rip-rap scour protection around a monopile foundation and combined wave and current loading. Results show that the methodology provides a complementary understanding of damage distribution to the maximum damage acquired from previous methodologies. In addition, it allows a comparison of damage characteristics between tests despite different shapes of the foundation. Research concludes that the size of the sub-areas influences significantly the damage description. Characteristic measures as the maximum damage number and standard deviation become stable at a grid ratio (Dn50)2/Asub equal to 1/4.

中文翻译：

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碎石丘冲刷保护中损坏的扩展表征

摘要 碎石冲刷防护装置损伤分析对装甲稳定性评估至关重要。以前的方法侧重于分析最大损坏数。这项工作引入了一种补充方法，可以根据子区域的灵活排列来确定和表征损伤统计分布。子区域是重叠的并且可以改变大小，从而可以进行精细的损坏分析。为了捕捉随子区域布局变化的损坏变化，该方法与损坏数量的统计评估相结合，这是通过定义装甲石尺寸和子区域尺寸之间的网格比 (Dn50)2/阿苏。该方法适用于单桩基础周围的大型抛石冲刷保护和波浪和电流组合载荷的两个稳定性测试的高分辨率测深测量。结果表明，该方法提供了对从先前方法获得的最大损伤的损伤分布的补充理解。此外，它允许对不同形状的基础进行测试之间的损坏特性进行比较。研究得出的结论是，子区域的大小对损坏描述有显着影响。当最大损伤数和标准偏差在网格比 (Dn50)2/Asub 等于 1/4 时变得稳定时的特征测量。结果表明，该方法提供了对从先前方法获得的最大损伤的损伤分布的补充理解。此外，它允许对不同形状的基础进行测试之间的损坏特性进行比较。研究得出的结论是，子区域的大小对损坏描述有显着影响。当最大损伤数和标准偏差在网格比 (Dn50)2/Asub 等于 1/4 时变得稳定时的特征测量。结果表明，该方法提供了对从先前方法获得的最大损伤的损伤分布的补充理解。此外，它允许对不同形状的基础进行测试之间的损坏特性进行比较。研究得出的结论是，子区域的大小对损坏描述有显着影响。当最大损伤数和标准偏差在网格比 (Dn50)2/Asub 等于 1/4 时变得稳定时的特征测量。