基于离散裂隙网络法和水流数值模拟技术的地下水封洞库水封性研究

A case study on water sealing efficieny of groundwater storage caverns using discrete fracture network method and flow numerical simulation

水封性是保证地下水封洞库安全运营的关键,目前研究地下水封洞库水封性的主要难点在于裂隙岩体含水层强烈的非均质性和各向异性。以某地下水封洞库工程为背景,通过实测裂隙几何参数分析裂隙发育特征,建立了研究区离散裂隙网络模型。之后对研究区进行网格化划分计算了各单元体渗透系数张量,基于对裂隙渗流基本规律的理解和假设建立了研究区高精度的非均质各向异性渗流模型,并对研究区渗透性特征进行分析。通过建立非均质各向异性渗流模型对水幕系统水封性能进行了探讨并与传统均质各向同性渗流模型进行对比分析,利用该模型可以弥补传统均质各向同性渗流模型的不足,更加准确地评价由于裂隙岩体非均质各向异性造成的储品泄漏风险。

Containment property is the key to ensuring the safe operation of groundwater-sealed caverns.At present, the main difficulty in studying the water sealing property of groundwater-sealed caverns lies in the strong heterogeneity and anisotropy of fractured rock aquifer.In this paper, a discrete fracture network model is established based on the measured fracture geometry parameters to analyze the fracture development characteristics.Based on the understanding and assumption of the basic law of fracture seepage, a high-precision heterogeneous and anisotropic seepage model is established, and the permeability characteristics of the study area are analyzed.Through the establishment of heterogeneous anisotropic seepage model, the water seal performance of water curtain system is discussed and compared with the traditional homogeneous isotropic seepage model.The model can make up for the deficiencies of the traditional homogeneous isotropic seepage model, and more accurately evaluate the storage leakage risk caused by the heterogeneity and anisotropy of fractured rock mass.