中文摘要：

针对两种不同初始相对密度的福建标准砂,开展了一系列偏应力恒定,球应力低速循环加卸载的应力路径三轴试验。研究了该应力路径下,初始密实度对饱和砂土体应变和剪应变发展规律的影响。结果表明：（1）随着循环次数的增加,体应变和剪应变均发生了明显的累积;（2）固结偏应力较小时,随着相对密度的增大,累积体应变明显减小,而累积剪应变略有增大,对循环体应变和循环剪应变几乎没有影响;（3）固结偏应力较大时,随着密实度的增大,累积体应变和累积剪应变,以及循环体应变和循环剪应变幅值均明显减小。随着循环次数的增加,密实度对循环剪应变的影响逐渐减弱,甚至消失。

英文摘要：

Stress-path triaxial tests of sand samples were conducted under constant deviatoric stress with low speed cyclic loading and unloading of spherical stress to study deformation mechanism of saturated sand with two different initial relative densities. Influences of initial relative density on volumetric strain and shear strain were examined, and the following results are obtained：（1） volumetric strain and shear strain are accumulated obviously as the number of cycle increases;（2） when consolidation deviatoric stress is small, accumulative volumetric strain decreases and accumulative shear strain increases with the increasing initial relative density, but it has no effects on cyclic volumetric stain or shear strain;（3） when it is large, these accumulative strains and cyclic volumetric and shear strains all decrease considerably with the increasing initial relative density. With the number of cycles increasing, the effects of initial relative density on cyclic shear strain decrease gradually, and even disappear.