颗粒级配对混合土力学性质影响的试验研究

Experimental study on effects of grain size distribution on mechanical properties of mixed soil

利用按质量比制备的黏土和细砂的混合土,开展混合土的固结快剪试验和压缩试验,探讨颗粒级配对混合土强度和变形特性的影响,基于分形维数对颗粒级配特征的定量描述,建立了混合土强度参数、变形参数与分形维数的函数关系。研究结果表明:分形维数较含砂量更好地反映了混合土强度和变形特性随着颗粒级配变化的规律,分形维数2.467(含砂量80%)为混合土力学性质明显变化的界限值,反映了颗粒级配渐变引起混合土力学性质突变的现象,为合理解释混合土力学特性变化提供了实验依据。

The sand-clay mixtures fabricated by mixing clay and fine sand were prepared with different dry mass ratios.The characteristics of strength and deformation of sand-clay mixtures were studied by using the consolidation direct shear test and the compression test.Based on the quantitative description of grain size distribution by fractal dimension,the function relationships between strength/deformation parameters and fractal dimension were established,respectively.The results showed that the fractal dimension was better than the sand content to reflect the change rules of strength and deformation with the grain size distribution.The fractal dimension2.467(the sand content=80%)was a threshold,which reflected the phenomenon of the abrupt change of the mechanical properties caused by the gradual change of the grain size distribution of sand-clay mixtures.This study can provide experimental evidence to reasonably explain the change of mechanical properties of sand-clay mixtures.