As the weak structure and main seepage channel of rock mass, the discrete fracture network (DFN) has a significant influence on the physical and mechanical properties of rock mass. In this paper, based on the rectangular joint model, two algorithms are proposed to realize the precise modeling of the DFN in any polyhedron. First, the equivalence of DFN modeling with the rectangular joint model and the elliptical joint model is theoretically deduced. On this basis, the chain splicing algorithm suitable for the rectangular joint model is proposed, which can generate the DFN model according to the actual distribution of joint spacing, trace, and bridge length. Aiming at the concave boundary in the model domain, the segmentation-stitching operation is put forward, and the continuity of the joint when passing through the interface is ensured. Finally, the effectiveness of the above algorithm is verified by several simple cases, and the relationship between the size of the geometrical representative elementary volume (REV) and discontinuity parameters is discussed. The results show that when the mean values of the joint distribution parameters are the same, even if the distribution rules are different, the number of joints generated in the same spatial region is approximately equal. The size of the geometrical REV is independent of the spacing and bridge length and is approximately three to five times the mean of the trace. The relevant algorithms and conclusions in this paper can be used as the basis for subsequent rock mass stability analysis and seepage calculation.

中文翻译：

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基于矩形节理模型的三维离散裂缝网络精确建模方法

离散裂隙网络（DFN）作为岩体的软弱结构和主要渗流通道，对岩体的物理力学性质具有显着影响。本文基于矩形关节模型，提出了两种算法来实现任意多面体DFN的精确建模。首先从理论上推导了DFN建模与矩形节点模型和椭圆节点模型的等价性。在此基础上，提出了适合矩形接缝模型的链式拼接算法，能够根据接缝间距、走线、桥长的实际分布生成DFN模型。针对模型域中的凹边界，提出分段缝合操作，保证接头穿过界面时的连续性。最后，通过几个简单的案例验证了上述算法的有效性，并讨论了几何代表单元体积（REV）的大小与不连续性参数之间的关系。结果表明，当关节分布参数均值相同时，即使分布规则不同，同一空间区域内产生的关节数量也近似相等。 REV 的几何尺寸与间距和电桥长度无关，大约是迹线平均值的三到五倍。本文的相关算法和结论可以作为后续岩体稳定性分析和渗流计算的基础。