The seabed failure poses a significant threat to the stability of marine structures. The actual wave-induced dynamic response in a porous seabed is a complex issue due to the randomness in hydrodynamic pressure and the spatial variability in soil properties. A probabilistic framework was proposed based on a 3-D stochastic finite element model for the investigation of the random wave-induced responses in a spatially heterogenous seabed. The framework integrates the generation of random waves as well as the random soil and the finite element analysis of poroelasticity via a Livelink code. A decomposed Karhunen-Loève expansion method was proposed, making the generation of multi-dimensional random fields with high resolution and large scale possible. Contrastive analyses of different scenarios were conducted to study the effects of the randomness of wave pressure and the spatial variability of the soil shear modulus on the seabed response. Monte Carlo simulations were used for the statistics of seabed response, and then the effects of the correlation length of random fields on the liquefaction depth were investigated. The results of the analysis highlighted the significant impacts of the randomness of ocean waves and the spatial variability in soil properties, which were often ignored in previous studies.

海底破坏对海洋结构的稳定性构成了重大威胁。由于流体动压的随机性和土壤性质的空间变异性，多孔海床中实际的波浪诱导动力响应是一个复杂的问题。提出了一种基于3-D随机有限元模型的概率框架，用于研究空间异质海床中随机波引起的响应。该框架通过Livelink代码集成了随机波以及随机土壤的生成和多孔弹性的有限元分析。提出了一种可分解​​的Karhunen-Loève展开方法，使高分辨率和大规模的多维随机场的生成成为可能。进行了不同情况的对比分析，以研究波浪压力的随机性和土壤剪切模量的空间变异性对海床响应的影响。利用蒙特卡罗模拟法对海床响应进行统计，然后研究了随机场的相关长度对液化深度的影响。分析结果突出了海浪的随机性和空间变异性对土壤特性的重大影响，而在以前的研究中常常忽略了这些影响。