荷载作用下超固结比对软土抗剪强度指标影响

Variation of soft clay strength index with over-consolidated ratio under load

通过室内三轴试验,研究在荷载作用下,淤泥质粉质粘土的超固结比与抗剪强度值的关系,进而分析总结出软粘土的抗剪强度指标c,φ值随超固结比和轴向偏应力的变化规律。表明:抗剪强度值随轴向偏应力的增加而线性增加;抗剪强度值随超固结比的增加而增加,呈曲线的变化趋势。超固结比越大,土样的抗剪强度增加的速率越慢。软粘土的抗剪强度指标c,φ值随轴向偏应力的提高而线性增加,但φ值增长幅度较小;软粘土的抗剪强度指标c,φ值随超固结比的增加而增加,呈曲线的变化趋势,超固结比越大,c,φ值增加的速率越慢;与c值相比,φ值增长幅度较小。最后对试验数据加以公式拟合,提出考虑荷载作用下软粘土的抗剪强度指标c,φ值随超固结比变化的计算公式。

Through indoor triaxial test, the relationship between over-consolidated ratio of the silt mass siltyclay and shear strength under load was studied in this paper. Then the variation of the shear strength index c,φ ofsoft clay with the over-consolidated ratio and the axial deviatoric stress was summarized. Test results show that theshear strength increases with the increase of the deviatoric stress; the shear strength increases with the increase ofover-consolidated ratio, the greater the over-consolidated ratio increases, the slower the shear strength of the soilsamples increases. c and φ increase linearly with the increase of the axial deviatoric stress, but φ increases in smallextent; the greater the over-consolidated ratio increases, the slower c and φ increase. Compared with c, φ increasesin small extent. Finally, formulae were used to fit the experimental data, and the formulae of the variation of softclay strength index c, φ with over-consolidated ratio under load were put forward.