该研究利用GDS动三轴仪开展了循环加载试验,系统分析了有效围压σ_3c'、循环应力比CSR及超固结比OCR对漫滩相软土累积塑性应变σ_z,ac^N、孔隙水压力u的影响规律。结果表明:σ_z,ac^N和u均随CSR增加而增大随OCR增加而减小。当竖向应力幅值不变时,σ_z,ac^N随σ_3c'的增大而减小表明预固结和围压对σ_z,ac^N有较好的抑制作用。随着振次的增加,当OCR越大时,滞回圈越小,且向应力轴偏移。当σ_3c'越大时,滞回圈越大,且向应变轴偏移。同时对累积塑性应变-振次曲线进行回归分析探讨了回归方程中拟合参数A、B与e、σ_3c'、CSR和OCR的关系,初步揭示了各因素对累积塑性应变的影响机理。

This study conducted cyclic loading tests using GDS dynamic triaxial apparatus and systematically analyzed the effects of effective confining pressure σ_3c' cyclic stress ratio CSR,and overconsolidation ratio OCR on the cumulative plastic strain σ_z,ac^N and pore water pressure u of soft soil in the floodplain phase.The results indicate that both σ_z,ac^N and u increase with the increase of CSR,and decrease with the increase of OCR.When the amplitude of vertical stress remains constant,σ_z,ac^N decreases with the increase of σ_3c',indicating that pre-consolidation and confining pressure have a good inhibitory effect on σ_z,ac^N.As the number of vibrations increases,the hysteresis loop becomes smaller and deviates towards the stress axis as the OCR increases.As σ_3c' increases,the hysteresis loop becomes larger and shifts towards the strain axis.At the same time,the regression analysis of cumulative plastic strain-vibration curve is carried out,and the relationship between fitting parameters A and B in the regression equation and e,σ_3c',CSR and OCR is discussed,and the influence mechanism of various factors on cumulative plastic strain is initially revealed.