基于频谱分析的二阶非线性随机波作用下海床液化概率计算  

Calculation of seabed liquefaction probability under second-order nonlinear random waves based on spectral analysis

作　　者：蔡明辉 杨明辉 杨汉 CAI Minghui;YANG Minghui;YANG Han(School of Architecture and Civil Engineering,Xiamen University,Xiamen 361005,China;Fujian Key Laboratory of Digital Simulations for Coastal Civil Engineering,Xiamen 361005,China)

机构地区：[1]厦门大学建筑与土木工程学院,福建厦门361005 [2]福建省滨海土木工程数字仿真重点实验室,福建厦门361005

出　　处：《海洋工程》2025年第2期102-113,共12页The Ocean Engineering

基　　金：国家自然科学基金资助项目(51678230);自然资源部丘陵山地地质灾害防治重点实验室自主项目(KLGHZ202104);中铁南方投资集团有限公司科技研究开发计划项目(202208)。

摘　　要：恶劣海况条件下由波浪荷载引起的海床液化是造成海洋结构物失稳的主要因素之一。为研究恶劣海况条件下海床最大液化深度的响应问题,首先将海洋波浪视为二阶非线性随机波,并以波浪频谱作为描述随机波浪的主要参数,推导了海床内部超孔隙水压力响应频谱与随机波频谱关系式。在此基础上,考虑了随机波浪荷载作用下海床动态响应计算结果的不确定性,依据基于瑞利变换的概率分析方法,结合二阶非线性随机波作用下超孔隙水压力动态响应解析解,提出了以频谱为基础计算参数的非线性随机波作用下海床土体液化概率的求解方法,该方法可直接计算不同深度处海床液化概率值,概率计算过程简便高效,并与他人的试验数据对比,验证了该方法的实用性。最后,利用Jonswap谱作为输入频谱进行分析,分析结果显示:有效波高Hs与显著波周期Ts的增大会增大不同深度处的海床液化概率,且最大液化深度也随之增加;而在相同的波浪等级下,最大液化深度随水深d的减小而增大;非均匀海床上覆土层的性质主导了海床的液化概率分布情况。Seabed liquefaction induced by wave loads under severe marine conditions is one of the primary causes of instability in offshore structures.To investigate the maximum liquefaction depth response of the seabed under adverse sea conditions,ocean waves are modeled as second-order nonlinear random waves,with wave spectra serving as the primary parameter to characterize random waves.The relationship between the seabed’s excess pore water pressure response spectrum and the random wave spectrum is derived.On this basis,the uncertainty of seabed dynamic responses under random wave loads is addressed,and a probability analysis method based on Rayleigh transformation is utilized.Combined with the analytical solution of the excess pore water pressure dynamic response under second-order nonlinear waves,a novel method for calculating the seabed liquefaction probability under nonlinear random waves is proposed,using wave spectra as the computational parameter.This method efficiently calculates liquefaction probabilities at different depths,and its practicality is validated through comparison with experimental data from other studies.Finally,the Jonswap spectrum is employed as the input spectrum for analysis.Results show that increases in significant wave height Hs and significant wave period Ts lead to higher liquefaction probabilities at various depths and a greater maximum liquefaction depth.Additionally,under the same wave conditions,the maximum liquefaction depth increases as the water depth d decreases.The properties of the overlying soil layer on a non-homogeneous seabed primarily govern the distribution of seabed liquefaction probabilities.

关 键 词：二阶非线性随机波 波浪荷载 海床动态响应 频谱 液化概率 

分 类 号：TV139.2[水利工程—水力学及河流动力学]