The conclusions have been deduced from the detailed analysis of a set of experimental results as below : 1 ) the formula of tangent young ' s modulus et has been established during the unloading process ; 2 ) the shearing features of the samples are similar to undrained test even though there are draining paths so the possion ratio of the sample is about 0 . 5 ; 3 ) unloading paths have little effects on the shearing strength parameters 通过对试验结果的分析得到: 1 )任一时刻土体的切线弹性模量公式; 2 )卸载情况下尽管存在排水通道,但试样仍基本上表现为不排水的性状,按广义虎克定律得到的泊松比在0 . 5附近; 3 )卸荷应力路径对土体的强度参数影响不大。