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天然裂隙岩体抗拉强度及破裂模式是岩体重要的力学特性,在一定程度上影响岩体的稳定.鉴于此,使用室内试验和数值模拟的方法探究了平行非共面闭合双裂隙岩桥倾角对巴西试样的抗拉强度和破裂模式的影响.结果表明:1)试样的抗拉强度随岩桥倾角的增大呈现先减小后增大的规律,且随着岩桥倾角增大试样的最终破裂模式受到预制裂隙的影响越大;2)Flatjoint模型中有效接触模量主要影响试样的弹模,黏结力与抗拉强度比主要影响试样的拉压强度比,并提出关于单轴压缩和巴西劈裂试验细观参数验证的一般过程;3)使用Smoothjoint模拟了闭合裂隙巴西试样,模拟结果与试验结果吻合较好,试样的破裂模式主要受到黏结力的分布影响;4)岩桥倾角在30°~60°时黏结力随加载的进行不断向试样中心聚集,而倾角在90°~120°时试样黏结力主要集中在裂纹的尖端,这是造成试样承载能力不同的主要原因.
Tensile strength and rupture mode of natural fractured rock mass are the important mechanical properties of rock mass and affect the stability of rock mass to a certain extent.In view of this, we use the indoor test and numerical simulation methods to explore the parallel non-coplanar closed double-fractured rock bridge The results show that: 1) The tensile strength of specimens decreases first and then increases with the increase of rock inclination, and with the increase of rock slope inclination The final fracture mode of the large sample is more affected by the prefabricated fracture. 2) The effective contact modulus in the Flatjoint model mainly affects the modulus of the specimen, and the ratio of the bond strength to the tensile strength mainly affects the tensile strength ratio of the specimen The general procedure for the verification of the micro-parameters of uniaxial compression and Brazilian cleavage tests is presented. (3) The closed fracture Brazilian specimens are simulated by using the Smoothjoint method. The simulation results are in good agreement with the experimental results. The rupture modes of the specimens are mainly affected by the distribution of the cohesion 4) When the inclination of rock bridge is between 30 ° and 60 °, the cohesive force keeps accumulating towards the center of the sample with loading, and the cohesion of the sample mainly concentrates at the tip of the crack when the dip angle is between 90 ° and 120 ° Sample load Mainly due to different forces.