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通过室内试验,利用数字图像相关方法(DICM)等研究手段,对含不同预置单裂纹的类岩石材料在单轴压缩下的裂纹扩展规律及岩体细观损伤演化机制进行系统研究。研究表明:预置单裂纹倾角?为15°和30°时,最大应变集中在预置裂纹的尖端靠内侧的位置,新裂纹为翼裂纹,起裂主要受张拉应力控制;当?增大到60°和75°时,最大应变集中区移动到裂纹尖端区域,新裂纹为次生裂纹,起裂主要受剪切应力控制;倾角?=45°时试样包含2条裂纹扩展路径,为2种裂纹类型转变的临界角度值;随着倾角?的增加,试样起裂应力逐渐增大;当?=30°时,试样的单轴抗压强度最低,裂纹的扩展速度最快;裂纹扩展主要受张拉应力控制时,试样的单轴抗压强度和起裂应力均显著低于主要受剪切应力控制时的情况。
Through laboratory experiments, the digital image correlation method (DICM) and other research methods were used to systematically study the crack propagation law and the evolution mechanism of the meso-scale damage of rock-like materials with different pre-existing single cracks under uniaxial compression. The results show that the maximum strain is concentrated at the tip of the prefabricated crack when it is 15 ° and 30 °, and the new crack is the wing crack. The initiation of cracking is mainly controlled by the tensile stress. At 60 ° and 75 °, the maximum strain concentration zone moves to the crack tip region. The new crack is a secondary crack, and the initiation of cracking is mainly controlled by the shear stress. When the angle φ = 45 °, the sample contains two crack propagation paths With the increase of the inclination angle, the stress at initiation of cracking gradually increases. When the bending stress is 30 °, the uniaxial compressive strength of the specimen is the lowest and the crack propagation speed is the fastest. When the crack propagation is mainly controlled by the tensile stress, the uniaxial compressive strength and initiation stress of the specimens are significantly lower than those under the primary shear stress control.