Dynamic Stability Analysis of Caisson Breakwater in Lifetime Considering the Annual Frequency of Severe Storm

• Published in: China ocean engineering Vol. 29; no. 2; pp. 287 - 300
• Main Author: 王禹迟 王元战 洪宁宁
• Format: Journal Article
• Language: English
• Published: Heidelberg Chinese Ocean Engineering Society 01.04.2015
• Subjects: Coastal Sciences; Engineering; Fluid- and Aerodynamics; Marine & Freshwater Sciences; Numerical and Computational Physics; Oceanography; Offshore Engineering; Simulation; Technical Notes; 暴雨; 概率评估; 沉箱; 波浪激励; 稳定性分析; 设计寿命; 防波堤; 随机波; lifetime; caisson breakwater; dynamic stability; annual storm frequency; wave spectrum
• ISSN: 0890-5487; 2191-8945
• DOI: 10.1007/s13344-015-0020-4

In the dynamic stability analysis of a caisson breakwater, most of current studies pay attention to the motion characteristics of caisson breakwaters under a single periodical breaking wave excitation. And in the lifetime stability analysis of caisson breakwater, it is assumed that the caisson breakwater suffers storm wave excitation once annually in the design lifetime. However, the number of annual severe storm occurrence is a random variable. In this paper, a series of random waves are generated by the Wen Sheng-chang wave spectrum, and the histories of successive and long-term random wave forces are built up by using the improved Goda wave force model. It is assumed that the number of annual severe storm occurrence is in the Poisson distribution over the 50-year design lifetime, and the history of random wave excitation is generated for each storm by the wave spectrum. The response histories of the caisson breakwater to the random waves over 50-year design lifetime are calculated and taken as a set of samples. On the basis of the Monte Carlo simulation technique, a large number of samples can be obtained, and the probability assessment of the safety of the breakwater during the complete design lifetime is obtained by statistical analysis of a large number of samples. Finally, the procedure of probability assessment of the breakwater safety is illustrated by an example.