中文摘要：

应用矩和L矩方法以及二次转换方程,基于模型试验数据的概率统计分析,研究半潜式平台在作业工况和生存工况下的气隙响应,以及平台垂向运动对立柱周围不同位置处的波浪升高和气隙的影响。结果表明,垂向运动总体上能够增加气隙,海况越恶劣,增加程度越明显；在不同浪向下对不同位置的气隙影响有差别,后立柱周围的波浪升高和气隙受平台运动的影响相比前立柱更为显著；同时,平台垂向运动会引起立柱周围波浪升高的非线性增强。

英文摘要：

Based on statistics of a model test and by using a moment/L-moment estimation method and a quadratic transformative equation,this paper mainly investigates the influence of vertical motions of a semi-submersible on airgap for operational cases and survival cases.It is concluded that vertical motions can generally increase airgap and the increased quantity is positively correlated to the severity of sea states.There exists a varied influence on airgap of vertical motions for different wave headings and locations：at back columns,airgap conditions can be much worse than those at front columns.Additionally,vertical motions can strengthen the nonlinearity of waves around columns.