随机波浪作用下饱和砂质海床弹塑性动力响应规律  

ELASTO-PLASTIC DYNAMIC BEHAVIORS OF SATURATED SANDY SEABED UNDER RANDOM WAVES

作　　者：王小雯 张建民[1] WANG Xiao-wen;ZHANG Jian-min(State Key Laboratory of Hydroseienee and Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《工程力学》2018年第6期240-248,256,共10页Engineering Mechanics

基　　金：国家自然科学基金面上项目(51678346);国家自然科学基金项目(59979012)

摘　　要：为研究实际海洋环境中随机性波浪作用下弹塑性海床饱和土体真实的动力学行为及振动液化过程演化规律,该文结合Biot动力固结理论和本课题组提出的砂土震动液化大变形本构理论模型和处理液化时零有效应力状态的数值算法,采用JONSWAP频谱来模拟波浪,给出了随机波浪作用下饱和砂质海床土体中超静孔隙水压力瞬态变化与液化过程的弹塑性动力分析方法。该方法可很好地描述在随机波浪作用下,海床土体内超静孔隙水压力场在时空上呈现出的瞬态起伏变化和平均单调累积增长或消散的特性以及海床内达到零有效应力的液化状态在时间域上间歇性出现、在空间域上连续性移动的规律性。In order to investigate the dynamic behavior and liquefaction process of soil in elasto-plastic saturated sandy seabed induced by random waves according to realistic ocean environment, an elasto-plastic method of dynamic analysis is put forward by integrating Biot＇s dynamic consolidation theory with an elasto-plastic constitutive model for sand liquefaction and the associated numerical algorithm at zero effective confining stress state proposed by our research group. The proposed elasto-plastic method is capable of reproducing wave-induced transient change of excess pore pressure and soil liquefaction in saturated sandy seabed, of which the random wave is formed based on JONSWAP spectrum. The numerical calculation illustrates a basic tendency that under random waves the excess pore pressure fluctuates transiently, and meanwhile it accumulates or dissipates averagely. It is always shown that liquefaction occurs intermittently at intervals in time domain and that the region of liquefied soil propagates continuously in space domain.

关 键 词：饱和砂质海床 弹塑性 随机波浪 液化 JONSWAP频谱 

分 类 号：TV139.26[水利工程—水力学及河流动力学]