中文摘要：

以天津海积软黏土为研究对象，对原状土及重塑土进行了不同固结压力、应力路径、加荷速率、排水条件下的三轴剪切试验，以应力比结构性参数与应变的关系来描述结构性衰减，研究了不同加荷模式下的结构损伤特性。结果表明，固结压力小于结构屈服应力时，剪切阶段的初始结构性和损伤速率基本不受固结压力影响，固结压力大于结构屈服应力时，初始结构性和损伤速率则随固结压力的增大而减小；在0〈θ〈π/2、π〈θ〈3π/2区间内，损伤速率随着应力路径方向角θ的增加而增加，在π/2〈θ〈π、3π/2〈θ〈2？区间内，损伤速率随着？的增加而减小，在每个π/2区间内，初始结构性随着？的增加先减小后增大；初始结构性和结构损伤速率随着加荷速率的增大而增大；排水剪切时的初始结构性和结构损伤速率都要比不排水剪时大。

英文摘要：

Based on Tianjin marine soft clay, triaxial tests are carried out on the intact soil and remolded soil in different test conditions, such as consolidation pressure, stress path, loading rate, drainage condition. The structural damage is described by the relationship between stress ratio structural parameter and strain. The character of structural damage under different loading modes is studied. The results indicate that when the consolidation pressure is below structure yielding pressure, the initial structure and damage rate in the shearing stage are not influenced by consolidation pressure. When consolidation pressure is above structure yielding pressure, the initial structure and damage rate decrease with the increasing of consolidation pressure. When the direction angle of stress pathθ is in the ranges of 0〈θ〈π/2 andπ〈θ〈3π/2, the damage rate increases with the increasing of angleθ. When the angleθis in the ranges of π/2〈θ〈πand 3π/2〈θ〈2π, the damage rate decreases with the increasing of the angleθ. In everyπ/2 range, the amount of initial structure falls and rises when the angle θ increases. The initial structure and damage rate increase with the increasing of shearing rate. The initial structural and structural damage rate in drained shearing are larger than that of undrained shearing.