Ao Yunhe, Sun Chuang, Jia Baoxin, Zhang Jianjun
School of Civil Engineering, Liaoning Technical University, Fuxin, 123000, Liaoning, People's Republic of China.
Sci Rep. 2022 Feb 22;12(1):2994. doi: 10.1038/s41598-022-06833-0.
In order to analyze the influence of meso-structure and meso-parameters on deep granite characteristics, a construction method of variable radius proportional clump model was proposed with particle flow method. The clump particle flow structure was constructed which suited the mechanical characteristics of granite. The deep cavern numerical calculation model of gradual particle density was constructed using the variable radius proportional clump model construction method, and the macroscopic fracture law of deep cavern surrounding rock was analyzed. The results show that meso parameters have lower effects on the compressive and tensile ratios of particle structures in the ball and clump models. It is also found that clump structure is greatly influenced by particle proportion and size while ball model is only slightly influenced by particle size. Furthermore, the compressive and tensile strength curves and fracture modes of numerical simulations and laboratory tests are in good agreement. In addition, the calculated results of the tunnel after simulated excavation are very close to the engineering practice. There are obvious shear failure areas on the right vault and left wall of the tunnel, and the shape and depth of the fracture area are basically the same.
为分析细观结构和细观参数对深部花岗岩特性的影响，采用颗粒流方法提出了变半径比例团聚模型的构建方法。构建了适合花岗岩力学特性的团聚颗粒流结构。利用变半径比例团聚模型构建方法建立了颗粒密度渐变的深部洞室数值计算模型，并分析了深部洞室围岩的宏观断裂规律。结果表明，细观参数对球体和团聚体模型中颗粒结构的抗压比和抗拉比影响较小。还发现团聚体结构受颗粒比例和尺寸的影响较大，而球体模型仅受颗粒尺寸的轻微影响。此外，数值模拟和室内试验的抗压强度、抗拉强度曲线及断裂模式吻合良好。另外，模拟开挖后隧道的计算结果与工程实际非常接近。隧道右拱顶和左壁存在明显的剪切破坏区，断裂区域的形状和深度基本相同。
