单轴压缩下含预制孔洞板状花岗岩试样力学响应的试验和数值研究

 利用挪威Iddefjord花岗岩试样加工制备含双侧预制方形孔洞的板状试样，并在Instron液压伺服控制试验机上开展单轴压缩试验，监测试样的应力、应变、声发射信号特征及试样破坏过程。研究发现，随着轴向应力的增大，试样在平行于孔洞竖直方向的位置相继出现劈裂裂纹并逐渐贯通，孔洞周边岩体出现块体弹射、片帮等应变型岩爆特征。试验研究表明，含孔洞花岗岩试样在单轴压缩下总是从孔洞周边的劈裂破坏开始，试样的声发射曲线比完整岩样存在更多的跳跃突变点。在此基础上，利用FLAC3D对室内试验进行数值模拟，通过线弹性模型分析含孔洞岩石材料的应力分布特性，通过应变软化莫尔–库仑准则模拟岩样的破坏过程，监测各计算时步下单元拉伸和剪切破坏特性；发现单轴压缩下含孔洞岩样的塑形破坏单元以拉伸破坏为主，拉伸破坏单元沿孔洞竖向边界贯通形成劈裂破坏面，这和室内试验观测结果是一致的。研究结果在一定程度上揭示了深部硬岩洞室开挖后，在高地应力作用下总是产生平行于洞室开挖边界面的板裂、片帮破坏现象。

EXPERIMENTAL AND NUMERICAL STUDIES OF MECHANICAL RESPONSE OF PLATE-SHAPE GRANITE SAMPLES CONTAINING PREFABRICATED HOLES UNDER UNIAXIAL COMPRESSION

The uniaxial compression tests of plate-shape granite samples containing two prefabricated holes on each side,prepared from Iddefjord granite blocks in Norway,are carried out by Instron hydraulic servo control testing machine in laboratory.The axial stress,axial and lateral strain,acoustic emission(AE) counts and failure modes of the samples are monitored during the tests.The splitting cracks occur near the holes' vertical surface and parallel to the loading direction when the loading stress increases to a ...