应力释放对结构性软土动力特性影响的试验研究

Experimental study about the effect of stress release on the dynamic characteristics of structural soft clay

软土现场取样引起的应力释放将对其动力特性试验指标产生影响。基于杭州某地区结构性软粘土的循环三轴试验,研究了软土在经历了应力释放过程的力学参数变化情况。结果表明,经历了应力释放并重新固结土样的孔压和变形增长速率较未经历应力释放的土样均有所降低,前者的动强度和剪切波速稍高于后者,但二者之间的差异很小。出于试验加荷精度及土体重固结情况的考虑,可以认为应力释放扰动对结构性软粘土动力特性的影响较小。

The stress release induced by field sampling of soft soil would affect the dynamic characteristic test index.Based on the cyclic triaxial test of structural soft clay in a certain area of Hangzhou,this paper studied the mechanical parameters of soft clay during the process of stress release.The results showed that the pore pressure and deformation growth rate of the re-consolidated soil samples after stress release were lower than that of the samples without stress release,the dynamic strength and shear wave velocity of the former were slightly higher than that of the latter,but the difference between them was very small.Considering the loading accuracy of the test and the reconsolidation of the soil,it could be considered that the stress release disturbance had little influence on the dynamic characteristics of structural soft clay.