基于嵌入式离散裂缝模型的裂隙型围岩隧道涌水量计算

Computing Water Inflow into Fractured Rock Tunnels Based on Embedded Discrete Fracture Model

摘要:

提出了一种基于嵌入式离散裂缝模型的裂隙型围岩隧道涌水量计算方法。该方法采用嵌入式离散裂缝显式表征岩体裂隙，通过引入流量交换项实现岩体基质流与裂隙流的耦合，规避了基质与裂隙网格的协调性约束，有效降低了网格划分的难度。通过与El-Tani解析解和COMSOL数值解的计算结果对比，验证了方法的有效性。进一步分析了裂隙间距、开度、倾角、长度及间隙等参数对涌水量的影响规律。最后，应用该方法计算南湾隧道涌水量，得到的最大裂隙涌水量与参考值量级一致，表明该方法可用于实际工程中隧道涌水量的初步评估。

Abstract:

This paper proposes an Embedded Discrete Fracture Model （EDFM）-based method for computing water inflow into fractured rock tunnels. The method explicitly represents rock fractures using embedded discrete fractures. By introducing flow exchange terms to couple matrix and fracture flow， it circumvents the conformity constraint between matrix and fracture grids， thereby significantly simplifying the meshing process. The validity of the method is verified by comparing its results with those obtained from the El-Tani analytical solution and COMSOL numerical simulations. Further analysis is conducted on the influence of fracture parameters—including spacing， aperture， dip angle， length， and gap—on water inflow. Finally， the method is applied to compute water inflow into the Nanwan Tunnel. The calculated maximum fracture-induced inflow is on the same order of magnitude as the reference value， demonstrating that the method is applicable for preliminary water inflow assessment in practical engineering.