1/4 圆弧面沉箱防波堤设计分项系数研究(英文)

The quarter-circular caisson breakwater (QCB) is a new type of breakwater, and it can be applied in deepwater. The stability of QCB under wave force action can be enhanced, and the rubble mound engineering can be less than that of semi-circular breakwaters in deepwater. In order to study the wave force distribution acting on the QCB, to find wave force formula for this type of breakwater, firstly in this paper, the distribution characteristics of the horizontal force, the downward vertical force and the uplift force on the breakwater were gotten based on physical model wave flume experiments and on the analysis of the wave pressure experimental data. Based on a series of physical model tests acted by irregular waves, a kind of calculation method, which was modified by Goda formula, was proposed to carry out the wave force on the QCB. Secondly, the reliability method with correlated variables was adopted to analyze the QCB, considering the high correlation between wave forces or moments. Utilizing the observed wave data in engineering field, the reliability index and failure probability of QCB were obtained. Finally, a factor Q=0.9 is given to modify the zero pressure height above SWL of QCB, and wave force partial coefficient 1.34 to the design expressions of QCB for anti-sliding, as well as 1.67 for anti-overturning, were presented.     

国内外防波堤损坏研究进展评述

近年来，深水环境下的防波堤建设项目日益增多，经常会遇到一些国际海岸工程中还未完全解决的难题。文章综述了国内外在防波堤损坏这一领域研究的历史与最新进展，并在此基础上对防波堤损坏的原因进行了初步探讨。     

《海岸工程手册》(CEM)将取代《海岸防护手册》(SPM)

1编写背景 自20世纪70年代起,美国工程兵团(USACE)和世界上大多数海岸工程作业都是在<海岸防护手册>(SPM)的指导下进行的.     

流场实景可视化在水运工程中的应用研究

在水运工程水动力数值模拟可视化中融入地理实景,能丰富视景信息,达到直观显示的目的。文章以Google地球软件(Google earth)作为虚拟场景的图形平台,对二维水动力数值计算流场进行动画仿真,实现了对数模计算成果的实景可视化。为实现实景可视化,首先要获取Google地球软件的视图窗口句柄,用Windows API通过自编程序对Google地球软件进行控制,然后在特定视角下既有的地理要素中融入实测地形图,依顺序在虚拟场景中分层绘制并显示逐时刻流场矢量图,从而实现流场动画。采用对局部屏幕图像截取方法获得不同时刻流场图像,将不同时刻的图像文件作为关键帧压缩编码生成动态影像文件。以实际人工岛建设工程项目为例,展示了实景动画可视化显示效果。     

港口吞吐量预测的混合算法实证研究

提出一种新的港口吞吐量预测混合算法，基于天津港的历史数据进行了实证研究。首先采用主成分分析和相关分析从影响港口吞吐量的社会经济指标中甄别出显著影响因子，其次采用基于时间序列分析的三次指数平滑法获得其预估值，最后采用基于因果分析的遗传算法优化的神经网络法预测港口吞吐量。结果表明，影响因子预估中基准年的选择对预测结果影响很大，中长期预测应采用多个连续基准年的平均预估值，以平滑影响因子增长率的波动。