围压增大条件下淤泥土弹性模量及侧向变形特性的真三轴试验研究

Research of True Triaxial Test of Elastic Ratio and Posisson's Ratio of Silt Soil under A Special Stress Path

保持大主应力、中主应力不变，增大小主应力是实际工程中可能存在的一种应力路径，土石坝蓄水和土方回填等就类似这种加荷方式。就该应力路径对宁波淤泥土进行了真三轴试验，针对真三轴试验结果，对本构关系中的弹性模量及反映侧向变形变化规律的泊松比进行了特定条件下的研究。结果表明，在这种应力路径下排水剪切，弹性模量和泊松比随围压的增大都呈不断减小趋势，这是岩土工程中应用广泛的邓肯模型和有限元分析中极少考虑的现象和结果。

Keeping maximum principle stress and medium principle stress fixed and increasing minor principle stress is a potential stress path, such as the impounding of earth and stone dam and the backfilling of earthwork in practical projects, under which several groups of true triaxial tests about silt soil from Ningbo city are studied.The true triaxial test result indicates that the trend of elastic ratio and Poisson's rations is getting downwards with the increasing of minorprinciple stress.These phenomena and results are seldom considered in Duncan- Chang model applied widely in practical projects and finite- element method analysis.