【作者】 崔颖；

【导师】 缪林昌； 经绯；

【作者基本信息】 东南大学 ， 岩土工程， 2006， 硕士

【摘要】 本文以国家自然科学基金课题“非饱和膨胀土的结构特征与结构强度研究”(批准号:40374047)为依托,应用非饱和土力学理论,通过对广西膨胀土排水剪切与不排水剪切以及控制吸力的固结试验,研究了广西膨胀土临界状态的特性以及不同吸力下的土体在p ? s平面内的屈服特征,取得了以下方面的成果:1.通过三轴试验研究了非饱和土体的临界状态特点,分析了其临界状态的特征及其影响因素以及状态参量在临界态下的变化情况,在此基础上拟合了临界状态方程,揭示了不同吸力下的土体在p ? s平面内的屈服特性。2.应用非饱和土固结仪进行了控制吸力的固结试验,通过试验结果,揭示了吸力对于固结特性的影响,在此基础上研究了不同饱和度下土体的固结特性。3.分析了膨胀土变形中微观与宏观的相互作用,研究了不同饱和度下土体的屈服形态;结合非饱和土弹塑性模型,通过试验确定了相关的模型参数,进一步研究参数的影响因素,在此基础上通过模型参数绘制出的LC屈服曲线与试验结果得到的曲线取得到了较好的吻合,为进一步构建模型奠定了基础。更多还原

【Abstract】 This thesis is a part of the project of“Research of structures and strength of unsaturated expansive soils”supported by National Natural Science Foundation of China (No.40374047). A series tests including drainage shear, undrainage shear and suction-controlled consolidation of Guangxi expansive soils were performed, and the critical state characteristics of Guangxi unsaturated expansive soils was studied based on the principle of unsaturated soil mechanics. The main results are obtained as follows:1. The critical state characteristics of unsaturated soils was studied by the trial-axial test results, and the infection factors of critical state of unsaturated soils were analyzed. Based on the experiment data, the critical state equation of unsaturated soils is used to calculate the critical state curves.2. A number of suction-controlled consolation test were performed on the remolded Guangxi expansive soils. The influence of suction on unsaturated soils behavior was investigated. The consolation characteristics for different degrees of saturation were studied and revealed yield characteristics in p-s plane of unsaturated soils which were controlled by different suction.3. The influence of macrostructure and microstructure to the deformation of unsaturated soils was studied. The elaso-plastic model was used to analyze the characteristics of unsaturated soils, and model parameters were calculated by the experiment data. The calculation results of LC curves are in good agreement with the experimental data.更多还原