饱和对水泥改良土抗压强度与弹性波速及其相关性的影响

Effect of Saturation on Elastic Wave Velocity and Compressive Strength of Cement Soil and Their Correlation

用固结不排水三轴剪切试验方法和透射法,分别测定改良土的抗压强度和弹性波速,从而研究饱和对水泥改良土抗压强度、弹性波速的影响以及两者的相关性。结果表明,水泥改良土含水量的变化对其强度、弹性波速的影响较大。试样饱和后,2种水泥改良土的抗压强度和剪切波速大约分别降低30%和20%左右,而压缩波速却明显增大。不同养护龄期、不同灰土配比条件下,饱和前后抗压强度与剪切波速具有一致的变化趋势,它们之间存在良好的相关性,其相关系数大于0.95;由于饱和导致改良土的压缩波速增加,不能反映其强度的弱化,因此,剪切波速是评价水泥改良土强度特性变化的重要指标。

The compressive strength and elastic wave velocity of cement soil are determined respectively by consolidation non-drainage triaxial shear test and transmission method so as to study the effect of saturation on the compressive strength, the elastic wave velocity and their correlation. Test results show that the effect of water content variations on the compressive strength and the elastic wave velocity is obvious. The static compressive strength and the shear wave velocity of two kinds of cement soil degrade 30 % and 20 % respectively, but the compressive wave velocity is notably increased after specimen saturation. Variations of the compressive strength and the shear wave velocity are same for unsaturated and saturated specimens which have different maintenance periods and cement soil ratios. Therefore, the good correlation between the compressive strength and the shear wave velocity can be developed and the correlation coefficient is greater than 0.95. Because the compressive wave velocity of saturated cement soil increases, it cannot be used to reflect the strength degradation after cement soil saturation. The shear wave velocity can be used to evaluate the variations of cement soil strength.