通过对温州典型饱和软黏土进行一系列不同应力路径下的部分排水循环动三轴试验，研究了部分排水条件下循环围压对饱和软黏土变形特性的影响。试验结果表明：部分排水条件下，与常规的围压保持恒定，偏应力单独循环作用下的三轴试验结果相比，循环围压的存在对饱和软黏土的永久体应变和永久轴向应变均产生了的显著的影响。在相同循环应力比和循环次数下，试样的永久体应变和永久轴向应变均随着循环围压幅值的增大而增大，说明常规的恒定围压循环三轴试验会低估高速交通荷载作用下路基土体的沉降。基于试样第10 000圈的永久体应变和永久轴向应变，分别建立了可以量化部分排水条件下循环围压对饱和软黏土永久体应变和永久轴向应变影响的经验公式，并用于预测饱和软黏土在交通荷载这种包含循环偏应力和循环围压耦合作用的复杂应力条件下产生的永久变形。

A series of partially drained cyclic triaxial tests under different stress paths are carried out on typical Wenzhou saturated soft clay. The influence of cyclic confining pressure on the permanent deformation behavior of saturated soft clay in partially drained condition is studied. The experimental results show that: in partially drained condition, comparing the test results from conventional cyclic triaxial tests with a constant confining pressure and deviator stress cyclically shearing alone, cyclic confining pressure has great influence on both the permanent volumetric strain and permanent axial strain. Under the same cyclic stress ratio, for a given number of cycles, both the permanent volumetric strain and permanent axial strain increase with the increasing of the amplitude of cyclic confining pressure, which indicates that the conventional cyclic triaxial tests with a constant confining pressure may underestimate the settlement of subsoils induced by traffic load. Based on the permanent volumetric strain and permanent axial strain after 10 000 cycles, two empirical formulas are proposed. They can quantify the effects of cyclic confining pressure on the permanent volumetric strain and permanent axial strain during tests on saturated soft clay under the partly drained condition, and can be used to predict the permanent deformation induced by traffic load including any combination with varying deviator stresses and varying confining pressures.