工程海域波浪特征分析方法比较

Comparison of wave characteristics analysis methods for project site

通过选取两个典型海外工程项目案例,分别采用波浪特征参数法和波浪谱法对工程海域波浪条件进行分析,并比较这两种方法在作业波浪条件、波浪特征认知程度上的差异,以及对海港水域平面布置产生的影响。对于波浪能量在频域及方向上存在多峰谱情况的海域,基于全谱的波浪特征参数系列数据有可能出现以下两种情况:1)主峰波向掩盖次峰波向;2)主峰波向错配次峰周期。对于上述两种情况,若仅采用波浪特征参数法对工程海域作业波浪条件进行分析,并指导海港水域平面布置,则极可能忽略或误判个别敏感波向、关键频域段的部分波浪能量,从而误导设计,为后续项目运营埋下隐患。对于以上情形,宜采用波浪谱法深入分析工程海域波浪能量在整个频域及各个方向上的详细分布及构成,并对关键波向、关键频域段的波浪能量进行量化,评估其对海港水域平面布置的影响,从而最大程度地避免由于波浪输入条件误判带来的风险。

In this paper,two typical overseas port projects are selected as examples to analyze the wave conditions at the project site using the characteristic wave parameters method and wave spectrum method respectively.A comprehensive comparison is then made of these two methods regarding the operational wave conditions as well as wave characteristics,and the influence on harbor water area layout design is analyzed in each case.For the sea area where there exist bi-modal spectrum waves,the full spectrum integrated characteristic wave parameters time series data has the following two disadvantages:1)The main peak wave direction“covers up”the secondary peak wave direction;2)The main peak wave direction“mismatches”the sub-peak period.For such a situation,if just applying the characteristic wave parameters method to analyse the operational wave conditions for the project site and then using it directly as a basis for harbor water area layout design,it is very likely to ignore or misjudge the wave energy of some sensitive directions and key frequency segments,hence misleading the design and burying risks for the follow-up project operation.For the above-mentioned situation,it is recommended to use the wave spectrum method to further analyse the wave energy distribution in the full frequency domain and all directions,and quantify the energy for the key direction sectors as well as the key frequency domain segments,and then evaluate its impact on harbor water area layout design.Thus,the risk caused by misjudgment of wave input conditions can be avoided to the greatest extent.