扬州土物理与力学性质指标的相关性分析

STUDY ON CORRELATIONS OF PHYSICAL AND MECHANICAL PROPERTY INDEXES OF YANGZHOU CLAYS

根据原状扬州各层土体的室内试验数据,采用数理统计的方法,研究了该地区土体的物理指标与力学参数间的相关性,并进行线性函数和指数函数拟合。研究结果表明:随着塑性指数的增加,压缩系数和体积压缩系数逐渐增大,内摩擦角和有效内摩擦角逐渐减小;土的黏聚力随着液限与天然含水量之差的增加而增加,随着液性指数的增加而减小,且黏聚力与液性指数间的相关性更好,当含水量超过液限时黏聚力不随上述两个参数的变化而变化;此外,压汞试验结果表明扬州原状土的孔隙结构均为明显的单峰孔径分布,其颗粒间孔隙的累计量随着塑性指数增大而增加;并且各层土体孔径分布的峰值所对应的孔径随着塑性指数的增大而减小。以上结果可以为扬州地区土体力学参数的估计提供参考。

The correlations of physical index and mechanical parameters,according to experimental data of Yangzhou clays,are investigated in this paper.The statistical results show that there is a positive correlation between the plasticity index and compressibility or bulk compressibility,while there is a negative correlation with internal friction angle or effective internal friction angle.Also,the cohesion decreases with the increase of liquid index,while it increases with the increase of the difference between liquid limit and water content.And the correlation coefficient of cohesion and liquid index is higher.However,if the water content is higher than the liquid limit,the cohesion is independent of the liquidity index or the difference value.In addition,the samples of Yangzhou clays exhibit obviously unimodal pore-size distribution(PSD),obtained from the mercury intrusion porosimetry tests on undisturbed clays.The volume of the inter-particle pores increases,while pore diameter corresponding to the peak of PSD decreases with the increase of the plasticity index.The above results provide a simple method for estimating the mechanical parameters of clay in Yangzhou area.