岩石中三维双裂隙组扩展和贯通过程的试验研究和弹脆性模拟

最新研制了一种完全透明、较低温度下拉压比可达1/6.6的树脂，其与岩石特性的相似性较前人的研究有大幅度提高。制作了一组含三维内置平行双裂隙组的试件，详细描述并分析了单轴加载下试件的裂隙扩展与贯通过程，研究其产生的条件和机制。试验结果表明：试件的破坏大致经历4个阶段，三维裂隙组的断裂比二维情况复杂得多，产生了多种不同形态的裂纹。在FLAC3D软件框架内建立了一种新的弹脆性本构关系，并采用超细单元和合理形态的网格建模。将数值模拟结果与相关试验进行对比，相符程度良好，表明新数值模拟方法的有效性。当双轴加载时，模拟结果也与前人类似试验结果有很好一致性。

Experimental studies and elasto-brittle simulation of propagation and coalescence process of two three-dimensional flaws in rocks

A team of specimens containing two parallel three-dimensional(3D) cracks are made of a newly developed resin，which is completely transparent and has more brittle fracture properties of rock-like material(tension-compression ratio is 1/6.6) than before at room temperature. The propagation and coalescence process of the cracks under uniaxial loading is described and analyzed in detail; and then its produce condition and mechanism are studied. The testing results show that the failure process of specimens can be divided into four stages. The fracture of 3D cracks, which produces many different forms of cracks, is much more complex than that of 2D cracks. Subsequently, the specimen is chosen to carry out the numerical simulation. By employing FLAC3D, the propagation process of the 3D cracks are simulated and studied by establishing a new elasto-brittle constitutive relation and using superfine and reasonable form of unit division. The numerical simulation results match well with the testing results in this paper and that obtained by former scholars, so as to show the effectiveness of the new numerical simulation method. Moreover, the simulation results also have a good consistency with the testing results obtained by former scholars under biaxial loading.