不同粘粒含量粉质土的动力强度特性研究

Study on Dynamical Intensity Features of Silt with Different Clay-Particle Contents

通过室内实验研究了黄河三角洲地区粘粒质量分数为3％～15％的饱和粉土动力强度特性。使用动三轴施加轴向动力，测得试样在动荷载作用下达到破坏时所需的振动次数及破坏过程中孔隙水压力的变化情况。试验结果显示每一组试样在不同循环应力作用下饱和粉土的破坏振次随剪应力比的增加而减小。通过对比分析不同粘粒含量粉土动强度特征曲线，得出粉土动强度对粘粒含量有很大的依赖性，在一定粘粒含量范围内，粉土动强度随粘粒含量增加先减小后增大。

The silt within which there is clay in a mass percentage between 3% and 15% are sampled from the Yellow River Delta Area. The dynamical intensity features of the saturated samples are studied in the laboratory, as the axial force is excerted on the sam- pie triaxises to detect the viberating frequency when it is broken, and the pressure varia- tion in the pore water during the breaking process. It is shown from the experimental results that the viberating frequency at the instant of the saturated sample breaking is decreased with the shear-stress-ratio increase when a group of the samples are effeeted by various cyclic stress. After the curves of the dynamical intensity features for the silt with various clay-particle contents has been analyzed and compared, it is learnt that the dynamical intensity greatly depends on the clay-particle contents. Within the studied range of the clay-particle, the silt dynamical intensity is decreased with the clay-particle content increasing, and becomes increased with its further increasing.