【摘要】 利用计算机断层扫描技术 (CT)对冻土在三轴剪切过程中的结构变化进行了动态测试 .通过对CT图像及CT数的分析发现 ,冻结粉质粘土在三轴剪切过程中和蠕变过程一样存在结构的弱化和强化现象 ,孔洞几何特征的改变和孔洞的长大与联合、土粒与土粒、土粒与冰粒之间的相互错动以及滑移是冻土粘塑性变形发展的重要原因 .冻土的结构损伤主要发生在冻土屈服之后 ,这部分损伤不能用CT数的变化来定量计算 .更多还原

【Abstract】 The structure changes in frozen silty clay under triaxial shear are dynamically monitored by Computerized Tomography(CT) technique. Analysis of CT images and CT numbers obtained in the test reveal there exist both structure strengthening and structure softening phenomena in triaxial compression. Visco plastic displacements of frozen soils are mainly induced by the changes of size, shape and unification of microscopic cavities, the slippages between soil particles and/or cemented ice particles. Most part of damage in the structure of frozen soils occurs after the soil yields, which belongs to visco plastic damage and can not be computed by CT numbers.更多还原