The stability of rock on mild slopes under wave attack

Momentarily the determination of the static stability of rock on mild slopes can be split in roughly two paths, the empirical and the physical approach. However, both the approaches have their limitations from which one could conclude that neither approach is currently an accurate description of the stability of rock on mild slopes under wave attack. The empirical approach by van der Meer [1988] has to be extrapolated outside its validity region and is deemed to be too conservative by Schiereck and Fontijn [1996]. The physical approaches on which the software XBeach-G[1], runs are capable of globally determining dynamic profile response reasonably well however they cannot accurately determine static stability. From this lack of an accurate approach to determine the stability of rock on mild slopes under wave attack, follows the research question of this thesis: “How should the stability or rock on mild slopes be described?” To determine how to describe the stability of rock on mild slope under wave attack, a test plan was set up. The test plan was split into two parts, firstly the empirical approach and secondly the physical approach. The empirical approach is based around the formula of Van der Meer [1988] for plunging waves. Whereas the physical approach follows the methodology of Xbeach-G. For which the input parameters have been derived by the means of a combination Bubble Image Velocimetry (BIV) and Particle Image Velocimetry (PIV).

当前，缓坡岩体的静稳定性判定大致可分为经验法与物理法两大路径。然而这两种方法均存在局限性，由此可推断，当前尚无一种方法能够准确描述波浪作用下缓坡岩体的稳定性。由van der Meer[1988]提出的经验法需在其有效适用范围外进行外推，Schiereck与Fontijn[1996]认为该方法过于保守。软件XBeach-G[1]所依托的物理法，虽能较为合理地全局判定动态剖面响应，却无法准确获取静稳定性结果。鉴于当前缺乏能够准确判定波浪作用下缓坡岩体稳定性的方法，本研究提出如下研究问题：“应如何描述缓坡岩体的稳定性？”为明确波浪作用下缓坡岩体稳定性的描述方法，本研究制定了试验方案。该试验方案分为两部分：其一为经验法路径，其二为物理法路径。经验法基于van der Meer[1988]提出的卷破波公式；而物理法则沿用XBeach-G的分析方法，其输入参数通过结合气泡图像测速法（Bubble Image Velocimetry, BIV）与粒子图像测速法（Particle Image Velocimetry, PIV）获取。