含预制裂缝大理岩试样单轴压缩实验研究

采用RMT-150B岩石力学伺服试验机对含预制裂缝的大理岩试样进行单轴压缩试验,分析了预制裂缝参数(裂缝倾角α=15°、30°、45°、60°、75°和裂缝位置l=25mm、37.5mm、50mm)对大理岩强度和破坏特性的影响。结果表明,应力-应变曲线随着预制裂缝倾角的增加,逐渐接近完整试样,受裂缝位置因素的影响相对较小;试样的峰值强度随预制裂缝倾角的增大,先小幅度增加,后发生减小,再剧烈增加,预制裂缝倾角很大程度地影响试样的破坏形式,并造成试样的强度差异;预制裂缝的扩展方向为偏离预制裂缝断面法线方向20°~90°范围;相比预制裂缝的位置因素,预制裂缝的倾角因素对岩石特性的影响更加显著。

Experimental study of uniaxial compression of marble samples with prefabricated cracks

In this paper, uniaxial compression experiment of marble specimens with prefabricated cracks was carried out by using RMT-150B rock mechanics servo test machine. The effect of prefabricated crack parameters (crack inclination angle α=15°, 30°, 45°, 60°, 75° and crack position l=25mm, 37.5mm, 50mm, respectively) on the strength and failure characteristics of marble were analyzed. Results show that with the increase of prefabricated crack inclination angle, the stress-strain curve gradually approaches the intact specimen, and is relatively less affected by the crack position factor. With the increase of prefabricated crack inclination angle, the peak strength of specimen increases by small amplitude first, then decreases, and finally increases sharply. The prefabricated crack inclination angle greatly affects the failure mode of specimen and causes the strength difference of specimen. The prefabricated crack affects the crack propagation direction, and the expansion direction is 20°~90° away from the normal direction of the prefabricated crack section. Compared with the positional factors of prefabricated cracks, the influence of the inclination factor of prefabricated cracks on rock properties is more significant.