岩体裂隙网络渗流模型及隧道掌子面渗流预测研究  

Study on fracture network model and permeability characteristics of rock mass in tunnel face

作　　者：雷林 左双英[1,2] 田娇[3] 刘晶 丁成元 袁霄 LEI Lin;ZUO Shuangying;TIAN Jiao;LIU Jing;DING Chengyuan;YUAN Xiao(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550025,Guizhou,China;Key Laboratory of Karst Geological Resources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,Guizhou,China;Guizhou Transportation Planning Survey and Design Institute Co.,Ltd.,Guiyang 550081,Guizhou,China)

机构地区：[1]贵州大学资源与环境工程学院,贵州贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵州贵阳550025 [3]贵州省交通规划勘察设计研究院股份有限公司,贵州贵阳550081

出　　处：《水利水电技术（中英文）》2023年第8期104-114,共11页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金(42167025);贵州省科学技术基金重点项目([2020]1Z052);贵州省科技重大专项计划(黔科合重大专项字[2018]3011)。

摘　　要：【目的】岩体的裂隙特征直接影响其渗流特性,随着隧道工程中与岩体裂隙渗流有关的突涌水问题日益突显,为提高隧道建设与维护的安全性及稳定性,建立一套隧道掌子面岩体裂隙渗流量的预测计算程序。【方法】基于MATLAB平台,利用Monte-Carlo随机模拟方法编制岩体裂隙二维网络模型生成程序及稳定渗流数值计算程序,研究了裂隙岩体表征单元体积(REV)的尺寸效应及渗透张量的确定方法。将该程序应用于某地铁隧道,在现场调查及裂隙参数统计的基础上,对隧道掌子面裂隙岩体稳定渗流量和渗透系数进行预测。【结果】结果显示:(1)掌子面岩体裂隙方向角服从正态分布,迹长及间距服从负指数分布;(2)裂隙岩体表征单元体(REV)的最佳尺寸为裂隙迹长均值的14倍;(3)计算了裂隙岩体的渗透系数椭圆、渗透张量及渗透主轴,分析结果表明该隧道掌子面裂隙岩体具有强烈的渗透各向异性特征。【结论】结果表明:岩体裂隙的网络模型对于隧道工程岩体的水力学问题研究有不可替代的作用。所编程序可以预测隧道开挖过程中掌子面的渗流量和渗透主方向,为采取经济、合理的地下水控制措施提供依据。[Objective]The fracture characteristics of rock mass directly affects its seepage characteristics.As the water gusher related to the fracture seepage of rock mass becomes increasingly prominent in tunnel engineering,a set of prediction and calculation program for the fracture seepage flow of rock mass on the tunnel face is established to improve the safety and stability of tunnel construction and maintenance.[Methods]Based on MATLAB platform,Monte-Carlo random simulation method was used to program the generation program of two-dimensional network model of fractured rock mass and the numerical calculation program of stable seepage flow.The size effect of representation unit volume(REV)and the determination method of permeability tensor of fractured rock mass were studied.The program is applied to a subway tunnel,and based on the field investigation and fracture parameter statistics,the stable seepage flow and permeability coefficient of the fractured rock mass on the tunnel face are predicted.[Results]The result showed that:(1)the direction Angle of the fracture in the face rock mass obeyed normal distribution,and the trace length and distance obeyed negative exponential distribution.(2)The optimum size of the representative unit(REV)of fractured rock mass is 14 times of the mean fracture track length.(3)The permeability coefficient ellipse,permeability tensor and permeability principal axis of the fractured rock mass are calculated.The analysis result show that the fractured rock mass at the tunnel face has strong permeability anisotropy characteristics.[Conclusion]The result show that the network model of rock mass fracture plays an irreplaceable role in the study of rock mass hydraulics in tunnel engineering.The program in this paper can predict the seepage discharge and main direction of the tunnel face during tunnel excavation,and provide a basis for taking economic and reasonable groundwater control measures.

关 键 词：裂隙岩体 MONTE-CARLO方法 MATLAB 裂隙网络模型 岩体渗透张量 

分 类 号：TU91[建筑科学—建筑理论]