冻融循环下含裂隙类岩石试件强度特性的研究

Study on Strength Characteristics of Fractured Rock Specimens Under Freeze-thaw Cycles

以水泥砂浆类岩石材料为研究对象,对冻融后的含裂隙类岩石进行单轴压缩实验,探讨经历不同冻融循环次数后的裂隙岩样在单轴压缩条件下峰值强度的变化情况,并和未冻融试件峰值强度进行对比.试验发现:砂子的颗粒越大,试件的孔隙率就越小,饱水时的含水率就越小,冻融破坏就相对越小;对干燥试件在冷冻情况下进行单轴压缩试验,试件的弹性模量相比室温下的试件更大,但峰值强度有所下降;试件的峰值强度随着冻融循环次数的增加而降低,而且降低的程度也随冻融循环次数的增加而增大;在相同的冻融循环次数下,试件的峰值强度随着预制裂纹的倾角的增大而增大.

Using cement-mortar-like rock materials as the research object,the uniaxial compression experiment was carried out to investigate the variation of peak strength of fractured rock specimens subjected to different freeze-thaw cycle times under uniaxial compression,and then made comparison with the peak strength of those non-freeze-thaw samples.Tests have found that the larger the sand particles,the lower the specimen porosity with less water,and thus the smaller damage the freeze-thaw will cause;the elastic modulus of the dried specimen in the frozen condition was larger than that of room temperature,but the peak strength decreased;the peak strength of the specimen decreases with the increase of the number of freeze-thaw cycles,and the degree of reduction is enlarged with the increased number of freeze-thaw cycles;at the same number of freeze-thaw cycles,the peak strength of the specimen is enhanced with the increased angle of the prefabricated crack.