时间延迟对劈裂试验条件下岩石凯塞效应的影响

验证了粗晶花岗岩在劈裂试验条件下凯塞效应的存在性。进行了循环加卸载时间间隔分别为2、15d和45d时岩石的声发射试验,讨论了时间延迟对花岗岩凯塞效应的影响。研究结果表明,前期荷载越接近极限强度,岩石的凯塞效应越不明显;凯塞效应随再次加载时间延迟的增加而削弱,在对花岗岩的声发射试验中观察到15d以后岩石的凯塞效应仍然很显著,45d后凯塞效应基本消失。文中同时对试件与加载设备之间的接触状态对声发射试验结果的影响作了初步的定性分析。

Influence of time-delay on Kaiser effect of rock under Brazilian tests

The existence of Kaiser effect was verified under Brazilian tests conducted on coarse-grained granite. Acoustic emission tests were respectively carried out after 2, 15 and 45 days time-delay since the preloading finished. Influence of time-delay on Kaiser effect were then discussed. The test results show that the closer the preloading stress to the ultimate strength, the less-pronounced the Kaiser effect is during reloading; and that the larger the time-delay, the faster the Kaiser effect decay. It is found from the Brazilain tests on granite specimens that Kaiser effect is still distinct after 15 days delay; and the effect disappears completely after time-delays of up to 45 days. The influence of friction contact between the specimen and apparatus on rock’s AE test results is also analyzed qualitatively.