复合加载模式下海床土体变形规律与失稳机理研究

Study On Deformation Law and Failure Mechanism of Seabed Sediment Under Combined Loading

海洋工程中结构物除了受到自身重力作用外,往往还受到海风、海浪、海流等的作用,使得海床土体中的基础一般受到集中力、弯矩和扭矩的联合作用,这一受力状态称为结构物基础的复合加载模式。本文以复合加载模式下海床土体变形规律与失稳机理为研究对象,基于通用有限元分析软件Abaqus,采用数值计算方法,对海床土体的极限承载能力进行了详细的研究。结果表明,荷载分量大小与组合形式对海床失稳机理与极限承载能力具有较大影响,H-M荷载空间内破坏包络面具有非对称性。本文给出的土体失稳模式,能够较为合理地评估复合加载模式下海床土体的变形规律;给出的土体极限力矩荷载判别准则,能够较为合理地计算海床土体的极限力矩荷载。

Some Ocean engineering structures are always in addition to withstand the vertical gravity loads,but also to horizontal loads induced by sea wind,sea wave and sea current,which make the foundation subjected to concentrated loads,moment loads and torque loads,the above loading state is termed as combined loading mode.In order to study the deformation law and failure mechanism of soil,the numerical analysis method is adopted to research the ultimate bearing capacity of seabed by usage of general finite element software Abaqus.The results show that there is a great influence on bearing capacity and deformation law for load components and combination forms in three-dimensional loading space;it is asymmetric of failure envelop in H-M loading space.The failure modes presented in this paper can evaluate the deformation law of seabed due to combined loading reasonably;and the ultimate moment loading criterion presented in this paper can calculate the ultimate moment loading reasonably.