不同温度循环作用后大理岩细观损伤特征的定量研究

Quantitative test on meso-damage characteristics of marble after different temperatures

通过单轴压缩试验和细观损伤特征量化试验,对经历20、100、300、450、600℃五种温度循环后的四川锦屏大理岩试样的宏观力学性质及相应的细观损伤特征进行了研究。试验结果表明:①经历不同温度循环的大理岩单轴压缩破坏试样的细观尺度微裂纹主要由沿晶裂纹、穿晶裂纹及晶内裂纹组成,且裂纹相应的基本几何信息服从广义极限统计分布特征;②由于试样中的沿晶裂纹和穿晶裂纹的100℃温度阈值特征,致使宏观尺度的大理岩试样在温度100℃前后表现出不同力学性质;③沿晶裂纹是在经历温度循环后大理岩试样单轴压缩破坏中起主导作用的微裂纹,穿晶裂纹有一定贡献,而晶内裂纹并未发挥显著作用。

Based on the uniaxial compression test and the quantitative meso-damage test,the mechanical properties and meso-damage characteristics of the Jinping marble in Sichuan Province after different high temperatures were studied.The temperature varied in the range of 20,100,300,450,600 ℃.The results show that there are three main microcracks,which are intergranular cracks,transgranular cracks and intracrystalline cracks,in marble specimens under uniaxial compression.The geometric parameters of the microcracks fit generalized extreme value distribution.There are the different mechanical properties under 100 ℃ and under higher temperatures because the threshold temperature of intergranular cracks and transgranular cracks is about 100 ℃.The intergranular cracks play a dominant role during the damge of marble samples.