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为了研究高含冰量冻结粉土的应力-应变关系及结构的内部损伤演化过程,利用SOMATOM-PLUS X射线螺旋CT机对-1、-2、-4℃下的冻结粉土进行了单轴压缩实时CT扫描试验,探讨了温度对高含冰量冻结粉土的宏观力学性能及微观损伤演化过程的影响。通过试验结果可以看出:冻结粉土的应力-应变关系曲线大致经历线弹性变形阶段、损伤演化阶段与峰后软化阶段;高负温下温度对冻结粉土初始弹性模量影响不是很明显,而对冻结粉土强度的影响则比较大;温度从-1℃降到-2℃,强度大约可以提高63%,而从-2℃降到-4℃,强度可以提高约为36%;CT扫描各层初始密度损伤并不完全相同,但各层密度随着应变变化的趋势大致相同,中环、全区的密度随着应变的增加而减小,外区密度则随着轴向应变的增加而增大。
In order to study the stress-strain relationship of high ice content frozen silt and the internal damage evolution of the structure, the frozen silt under -1, -2 and -4 ℃ was uniaxially compressed using SOMATOM-PLUS X-ray CT scanner CT scanning test to investigate the effect of temperature on macroscopic mechanical properties and microscopic damage evolution of frozen icing clay with high ice content. The test results show that the stress-strain curve of frozen silt mainly undergoes linear elastic deformation stage, damage evolution stage and post-peak softening stage. The effect of temperature on the initial elastic modulus of frozen silt is not obvious at high negative temperature, While the effect on the strength of frozen silt is relatively large. When the temperature drops from -1 ℃ to -2 ℃, the strength can be increased by about 63%, while the strength can be increased by about 36% from -2 ℃ to -4 ℃. CT The initial density of the scanned layers is not exactly the same, but the densities of the layers vary with the densities. The densities of the middle and the whole regions decrease with the increase of the strain, while the densities of the outer regions increase with the increase of the axial strain Increase.