非共面闭合裂隙巴西圆盘试验与颗粒流模拟研究

发布时间：2018-12-19 21:25

【摘要】：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.
[Abstract]:The tensile strength and fracture mode of natural fractured rock mass are important mechanical properties of rock mass and affect the stability of rock mass to some extent. In view of this, the influence of the inclination angle of the parallel non-coplanar closed double-fissure rock bridge on the tensile strength and fracture mode of the Brazilian specimen is investigated by laboratory test and numerical simulation. The results show that: 1) the tensile strength of the specimen decreases first and then increases with the increase of the inclined angle of the rock bridge, and the final fracture mode of the specimen increases with the increase of the inclination angle of the rock bridge. 2) in the Flatjoint model, the effective contact modulus mainly affects the elastic modulus of the specimen, and the ratio of bonding force to tensile strength mainly affects the tensile strength ratio of the specimen. 3) Smoothjoint was used to simulate the Brazilian specimen with closed fracture. The simulation results are in good agreement with the test results, and the fracture mode of the specimen is mainly affected by the distribution of the bonding force. 4) when the inclination angle of rock bridge is 30 掳~ 60 掳, the bond force is continuously gathered to the center of the specimen with the loading, while the bond force of the specimen at 90 掳~ 120 掳is mainly concentrated at the crack tip, which is the main reason for the different load-bearing capacity of the specimen.
【作者单位】：中国矿业大学深部岩土力学与地下工程国家重点实验室;中国矿业大学力学与建筑工程学院;
【基金】：江苏省杰出青年基金项目(BK20150005) 江苏省双创团队项目(2014年)
【分类号】：TD313

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