基于分形理论的三维岩体裂隙网络非线性渗流机理研究

Rock fracture network is the main paths of fluid flow and contaminant transport, and its permeability plays an important role in the safety assessment of deep underground engineering. This work extensively investigates the nonlinear flow and fractal properties of three-dimensional rock fracture networks by applying theoretical analysis, flow test, and numerical simulation. First, based on the fractal scaling law and the 3D printing techniques, both the experimental and numerical models of three-dimensional rock fracture networks are constructed, and by sealing the models using the inflow and outflow tanks, high accuracy testing system and method are established. Second, a set of nonlinear governing equations of fluid flow in three-dimensional rock fracture networks are solved using a self-developed code on the basis of the rank-one inverse Broyden quasi-Newton method. Finally, the mathematical relationships between permeability of three-dimensional rock fracture networks and geometric parameters are proposed, and the conditions for predicting the onset of nonlinear flow are suggested. The expected results have important theoretical meanings and can provide valuable technical supports for the design, excavation and management of underground projects.

岩体裂隙网络是流体流动和污染物运移的主要载体，其渗流特性是评估深部地下工程安全性的重要参数。本项目拟采用理论分析、室内试验和数值模拟相结合的方法，对三维空间中裂隙的几何分布特征及非线性渗流特性进行深入研究。首先，基于分形理论和3D打印技术重构复杂三维岩体裂隙网络试验物理模型和数值模型，施加进出口密封装置，建立三维岩体裂隙网络高精度渗流试验系统和试验测试方法；其次，基于逆Broyden秩1拟牛顿迭代法自编程序求解三维岩体裂隙网络非线性渗流方程组，建立复杂三维岩体裂隙网络非线性渗流计算平台；最后，建立三维岩体裂隙网络渗透系数与裂隙网络几何参数之间的数学关系，提出复杂三维岩体裂隙网络非线性渗流判据及预测方法。项目预期成果具有重要理论意义，并可对工程设计、施工和管理提供借鉴。

岩体裂隙网络是流体流动和污染物运移的主要载体，其渗流特性是评估深部地下工程安全性的重要参数。本项目拟采用理论分析、室内试验和数值模拟相结合的方法，对三维空间中裂隙的几何分布特征及非线性渗流特性进行了深入研究。首先，基于分形理论和3D打印技术重构复杂三维岩体裂隙网络试验物理模型和数值模型，施加进出口密封装置，建立了三维岩体裂隙网络高精度渗流试验系统和试验测试方法；其次，自编程序求解三维岩体裂隙网络非线性渗流方程组，建立了复杂三维岩体裂隙网络非线性渗流计算平台；最后，建立了三维岩体裂隙网络渗透系数与裂隙网络几何参数之间的数学关系，提出了复杂三维岩体裂隙网络非线性渗流判据及预测方法。项目预期成果具有重要理论意义，并可对工程设计、施工和管理提供借鉴。.在IJRMMS等期刊发表论文30篇, 国家发明专利授权或公开7项（第一6项）；刘日成研究员入选中国科协青年人才托举工程，获中国岩石力学与工程学会青年科技奖（金奖），担任日本学术振兴会特聘研究员、JRMGE期刊编委、CSRME日本分会秘书长。