中文摘要：

利用固结试验与三轴压缩试验对天津海积软土结构特性进行了分析,研究表明结构性土随试验条件不同其结构屈服应力也有所不同。应用刚度比与应变的关系描述了结构损伤速率随围压的变化情况,损伤速率在结构屈服之前随围压增大而增大,当围压等于固结结构屈服应力时达到峰值,在结构屈服之后随围压增大逐渐减小。对初始切线模量与偏应力之间的关系进行了分析,结果表明初始切线模量随偏应力变化呈倒抛物线状。最后考虑围压和偏应力的影响,建立了结构性土的修正邓肯-张模型,并基于试验数据对模型进行了验证。

英文摘要：

Mechanical properties of soil are significantly affected by its structural behavior. The structural behavior of marine soft soil in the Tianjin region is analyzed based on one-dimensional consolidation tests and triaxial compression tests. The conclusion is drawn that the structural yield stress varies with test conditions.Change in the rate of structural damage with the confining pressure is described by using the correlation between rigidity ratio and strain. The rate of structural damage increases with the rising confining pressure before the structure yield,reaches a peak value when the confining pressure is equal to the structural yield stress,and gradually falls after the structure yield. The function expression between the initial tangent modulus and the deviatoric stress is found and a figure like the inverted parabolic shape is shown. Considering the influence of the confining pressure and the deviatoric stress,the modified Duncan-Chang model of structural soils is obtained. The result of this model is so well verified by the corresponding test data that the stress-strain curve of structural soils can be characterized by this model.