基于随机有限元法的波致海床响应概率分析  

Probabilistic analysis of wave-induced seabed response based on stochastic finite element method

作　　者：朱彬 裴华富 杨庆[3] 卢萌盟 王涛 ZHU Bin;PEI Hua-fu;YANG Qing;LU Meng-meng;WANG Tao(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116 [3]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《岩土力学》2023年第5期1545-1556,共12页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.52209150,No.52178373);中国博士后科学基金面上资助(No.2022M723403);中央高校基本科研业务费专项资金(No.2022QN1026)。

摘　　要：波浪荷载作用下的海床响应是岩土工程领域的研究热点,波致海床液化是导致海床及结构物失稳的主要原因。针对海床响应分析中涉及的诸多不确定性因素,如沉积物参数的空间变异性以及荷载的随机性,建立了基于随机有限元方法的概率分析框架,将在MATLAB中实现的空间异质土体的模拟与在COMSOL中实现的孔隙弹性有限元分析通过LiveLink程序进行耦合。提出了一种分解的Karhunen-Loève(简称K-L)展开方法,该方法占用较少的计算时间和内存空间,使得高分辨率、大尺寸的三维随机场的模拟更加高效。应用上述概率框架分别对规则波浪荷载作用下的二维倾斜海床以及随机波浪荷载下的三维海床响应进行了研究,揭示了海床土体渗透系数K与剪切模量G的空间变异性以及波浪荷载随机性对孔隙水压力分布和海床液化深度的影响规律,表明了传统确定性分析方法将导致不安全的工程设计。Wave-induced seabed response is a research hotspot in the field of geotechnical engineering.The wave-induced seabed liquefaction is the main reason for the instability of seabed and marine structures.In view of many uncertainties involved in the analysis of the seabed response,such as the spatial variability of sediment properties and the randomness of related loads,a probabilistic framework based on the stochastic finite element method is developed,which couples the simulation of spatially heterogeneous soil in MATLAB and the finite element analysis of poroelasticity in COMSOL through the Live Link program.A decomposed K-L expansion method is proposed,which takes less computational time and memory space,making the generation of three-dimensional random fields with high resolution and large scale more effective.Based on the proposed probabilistic framework,the dynamic response of both the two-dimensional sloping seabed under regular waves and the three-dimensional seabed under random waves are studied.The influence of the spatial variability of the permeability coefficient K and shear modulus G of marine sediments and the randomness of wave loads on the distribution of pore water pressure and the liquefaction depth in the seabed are revealed.The study has shown that traditional deterministic analysis methods lead to unsafe engineering designs.

关 键 词：波浪荷载 海床响应 随机场 空间变异性 随机有限元法 

分 类 号：TU433[建筑科学—岩土工程]