通过静、动三轴试验,研究了初始剪应力对软粘土应力-应变关系、应力路径、孔压和强度的影响。研究结果表明,随着初始剪应力的增大,动应变和孔压增大,土体将在较小的循环次数下发生破坏。以转折应变为破坏标准,得到了不同初始剪应力下软粘土的动强度曲线;随着初始剪应力的增大,土体动强度减小。当不存在初始剪应力时,动强度随破坏循环次数的增多而衰减得较快,当初始剪应力较大时,其衰减缓慢。
The effect of initial shear stress on stress - strain relationship, stress track, pore water pressure and strength is investigated by static and dynamic triaxial tests. It is observed that with the increase of initial shear stress, the dynamic strain and pore water pressure increase and the clay destroies under small number of cyclic cy- cles. Taking the turning strain as the failure criterion, the dynamic strength curves of soft clay with different initial shear stress is obtained. It shows that the dynamic strength decreases with the increase of initial shear stress. The dynamic strength of soft clay degrades fairly rapidly with the number of failure cycles when there is no initial shear stress. However, the cyclic shear strength degrades slowly when there is a bigger initial shear stress.