基于CT单向压缩试验的冻结重塑兰州黄土损伤耗散势研究

Damage dissipation potential of frozen remolded Lanzhou loess based on CT uniaxial compression test results

首先分析了冻土损伤的物理本质,然后在改进了的与CT试验机配套使用的三轴试验仪基础上,进行了一系列的单向压缩试验过程的CT扫描,获得了冻结重塑兰州黄土试样的屈服应变、损伤应变临界值、破坏应变临界值;发现如果用塑性应变表示损伤阈值,则温度越低、试样的损伤阈值越大;最后通过CT数定义损伤变量,获得了冻结重塑兰州黄土的损伤演化规律和损伤耗散势函数。

The physical nature of frozen soil damage is analyzed.A series of CT scanning during the uniaxial compress test process is conducted on an enhanced triaxial system which works together with the CT system.According to the test results,the yield strain,damage strain critical value,and failure strain critical value of the frozen remolded Lanzhou loess are obtained.Then,the plastic strain is used to describe the damage threshold value.The lower the temperature,the larger the damage threshold value.In the end,the CT value is used to define damage variable,and the damage evolution law is derived based on the results of CT scanning tests.A damage potential function suitable for frozen soil is proposed.