不同应力路径下宁波粘土K_0固结三轴试验研究

利用GDS多功能三轴仪对宁波地区原状粘土进行了不同应力路径作用下K0固结三轴压缩试验,探讨了增P、等P和减P3种应力路径条件下宁波粘土的应力-应变、孔隙水压力和强度特性,并结合试验结果分析了粘土的总应力路径和有效应力路径特性。结果表明,总应力路径和有效应力路径的变化趋势基本一致,不同应力路径下q-ε1非线性关系明显,土体呈现弱软化型;不同应力路径下土的峰值强度和土中孔隙水压力差异明显;应力路径对粘聚力影响较大,对内摩擦角影响不大,有效强度指标则呈相反趋势。

Triaxial Compression Test of K0 Consolidated Ningbo Clay Under Different Stress Paths

Triaxial compression test of K0 consolidated Ningbo undisturbed clay under different stress paths is executed by using GDS triaxial instrument. The stress-strain, pore pressure and strength behaviors of Ningbo clay under three kinds of stress paths, i. e. , DE （increase p）, DG（constant p） and DE（reduce p） are discussed. The total and effective stress paths property of clay is analyzed using the test result. It is shown that the tendency of total and effective stress paths is identical, the stress strain q-ε1 presents obviously nolinear relation and weak softening type. The peak value strength of Ningbo clay and pore pressure has a great difference under different stress path. In addition, stress path has a great influence on cohesive strength, but a little effect on internal friction angle in case of total stress, and conversely in case of effective stress.