波浪荷载作用下近海粉质土液化特性及动本构关系的试验研究与理论分析

项目名称： 波浪荷载作用下近海粉质土液化特性及动本构关系的试验研究与理论分析

项目编号： No.51278466

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 建筑科学

项目作者： 王国才

作者单位： 浙江工业大学

项目金额： 80万元

中文摘要： 本研究采用理论、试验与数值模拟相结合的方法，系统研究波浪荷载作用下杭州湾典型近海粉质土的液化特性。在研究中，采用循环动三轴和循环剪切试验分析近海粉质土的动应力-应变关系、动强度和累积孔压关系，分析振动频率、振次、固结比、围压、初始主应力方向、中主应力系数等参数以及细粒和粉粒含量对循环累积孔压比的影响，建立循环应变下的累积孔压比和衰化动变形归一化关系和动孔隙水压力上升模型；基于塑性力学基本原理和室内试验结果建立等效粘弹塑性动本构模型并将其引入到波浪荷载作用下饱和粉质土层的动力反应分析程序中；利用不等应力幅值的循环三轴试验结果标定粘弹塑性动本构模型和动孔隙水压力上升模式并对不等应力幅值的循环三轴试验进行动力反应数值模拟，提出一种判别近海粉质土在动荷载下液化可能性的方法。本研究可进一步丰富和完善现有土动力学基本理论，为近海粉质土在动荷载下液化可能性和海床与近海结构物地基稳定性的评判提供理论依据。

中文关键词： 波浪荷载；海床；动力反应；液化；试验

英文摘要： The liquefaction characteristics of typical offshore silty soils in the area of Hangzhou Bay are investigated in details using theoretical, experimental and numerical simulation methods. In the analysis, the dynamic stress- strain relationship and the dynamic strength- cumulative pore pressure relationship of offshore silty soils are analyzed using cyclic dynamic triaxial tests and cyclic shearing tests, where the effect of the parameters, such as frequency, vibration times, consolidation ratio, confining pressure, initial orientation of principal stress, coefficient of intermediate principal stress and the clay particle content and silt particle content, etc., on the cyclic cumulative pore pressure, is studied. The normalized relation of cumulative pore pressure ratio and degraded dynamic deformation and dynamic pore water pressure rising model are established under the condition of cyclic strain. Based on the principal of plasticity and lab experimental results, the equivalent visco-elastoplastic dynamic constitutive model is established and introduced into the dynamic analysis program of saturated silt layer under wave loading. The proposed visco-elastoplastic dynamic constitutive model and dynamic excess pore water pressure rising model are calibrated using the experimental data of cyclic triaxial tests and

英文关键词： water wave loading；seabed；dynamic response；liquefaction；test