论文部分内容阅读
应用FLAC3D软件对含预制裂纹砂浆块和完整砂浆块试样在单轴压缩点荷载作用下的破碎过程进行了数值模拟.结果表明:完整砂浆块的破碎过程首先出现一个应力集中区,形成密实核,然后形成中间裂纹、径向裂纹、侧向裂纹,这些裂纹迅速扩展,并衍生许多新的次生裂纹,沿着剪切或拉应力迹线贯通整个岩块;而含预制裂纹岩块的破碎则是在出现密实核后,随之在裂纹的两个端部出现应力集中,然后沿主载荷方向扩展,形成翼型裂纹,最后贯通整个试件;含预制裂纹试件和完整岩块的破碎应力-侵深曲线均出现跃进式特征,但裂纹试件裂尖局部的应力集中导致了翼型裂纹的产生并且沿主应力方向扩展,较早导致试件的破碎,其临界失稳荷载明显下降,预制裂纹对试件破碎效果的影响是显著的.
FLAC3D software is used to simulate the crushing process of prefabricated cracked mortar blocks and intact mortar blocks under uniaxial compression point load.The results show that the crushing process of a complete mortar block first appears a stress concentration zone to form a dense core , Followed by the formation of intermediate, radial and lateral cracks. These cracks rapidly propagate and generate many new secondary cracks that penetrate the entire rock mass along the shear or tensile stress trajectory. However, fragmentation with pre-cracked rock masses Then appear dense nuclei, followed by stress concentration at both ends of the crack, and then spread along the main load direction, the formation of airfoil cracks, and finally through the entire specimen; with prefabricated crack specimens and complete rock crushing The stress-in-depth curves show the leaping characteristics. However, the local stress concentration at the tip of the cracked specimen leads to the generation of airfoil cracks and its propagation along the principal stress, which leads to the earlier fracture of the specimen and the significant decrease of the critical load , Prefabricated cracks on the impact of the crushing effect is significant.