溶孔-裂隙复合网络的随机生成及其数值网格化  

Stochastic generation and numerical gridding of dissolved pore-fracture composite networks

作　　者：鲁海峰[1] 宁明诚 张元 梁修雨 Lu Haifeng;Ning Mingcheng;Zhang Yuan;Liang Xiuyu(School of Earth and Environment,Anhui University of Science and Technology,Huainan Anhui 232001,China;School of Environment Science and Engineering,Southern University of Science and Technology,Shenzhen Guangdong 518000,China)

机构地区：[1]安徽理工大学地球与环境学院,安徽淮南232001 [2]南方科技大学环境科学与工程学院,广东深圳518000

出　　处：《地质科技通报》2023年第5期264-272,共9页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金项目(41977253)。

摘　　要：煤层底板岩溶裂隙含水层导致底板突水问题受到广泛关注,掌握含水层渗流特征是减少此类事故发生的关键,而在此之前应首先建立合理的含水层模型。岩溶裂隙含水层具有裂隙和岩溶两种复合网络介质特征,针对此类问题主要采用数值模拟方法进行研究,而多数成果仅对含水层中的裂隙网络进行分析,忽略了其中随机分布的溶孔等岩溶现象,与实际情况差异较大。重点对灰岩含水层中随机分布的溶孔进行模拟,并将其与裂隙网络模型结合,得到准确度较高的灰岩含水层网络模型,并将其数值化。为此选取了钻孔揭露及露头资料,用AutoCAD软件描绘溶孔轮廓建立了溶孔形态库,为溶孔的随机生成提供了足够的样本支撑,溶孔样本足够多时,溶孔形态库就具有很高的真实性;其次利用多因素定向块体切割技术建立了溶孔储存空间,随机从中提取溶孔,按照一定比例缩放并置于储存空间内,就可以实现随机溶孔模型的生成。随后将其与基于蒙特卡洛法生成的裂隙网络叠加,从而得到具有一定溶孔率和裂隙密度、间距的灰岩含水层复合网络模型。最后基于AutoCAD软件将网络模型转化为FLAC^(3D)数值网格,即建立灰岩含水层数值模型,由此生成具有不同溶孔率和裂隙密度、间距的复合网络模型。对裂隙网络中的裂隙密度和延展性分别按低、较低、中等、较高、高进行分类;将溶孔模型中的溶孔率设为0.05,0.10,0.15,0.20,0.25,0.35。以高密度-低延展性裂隙网络为例,选取了溶孔率为0.05和0.25的溶孔模型与其叠加,对复合网格中的裂隙迹长、溶孔长轴比和倾角进行统计,结果符合预期,从而证明所生成模型的有效性。研究成果对于三维随机溶孔模型的建立具有一定参考意义,为后续基于数值模拟分析岩溶裂隙含水层的渗流特征奠定了模型基础。[Objective]The problem of water inrush caused by karst fissure aquifers in coal seam floor has been widely concerned.The key to reduce the occurrence of such accidents is mastering the seepage characteristics of aquifer.Before that,an accurate and reasonable aquifer model should be established first.[Methods]The karst fractured aquifer has the characteristics of composite network.At present,the numerical simulation method is mainly used to resolve this kind of problem.However,most of the existing numerical models only simulate the fracture network of aquifer,ignoring the karst phenomena such as dissolved pores with stochastic distribution,which is different from the practice.Therefore,this paper focuses on the simulation of randomly distributed dissolution pores in limestone aquifers,and combines them with the existing fracture network to obtain a more accurate karst featured aquifer network model,then convert it into a numerical ones.For this reason,firstly,some drilling and outcrop data are selected,and the contour of dissolved pores is depicted by AutoCAD software to establish corresponding morphological library,which provides sufficient samples for the stochastic generation of dissolved pore.When there are enough dissolved pore samples,the authenticity of the morphological library of dissolved pores are maintained.Secondly,the multi-factor directional block cutting technology is used to establish a storage space for the subsequent random dissolved pores.The dissolved pores are randomly extracted from corresponding morphological library,after scaling and rotating these samples into the storage space according to a certain scaling ratio,and finally the stochastic generation of dissolved pores can be realized.Subsequently,superimposed it with the fracture network generation based on the Monte Carlo method to obtain a randomly generated limestone aquifer composite grid model with a certain dissolved porosity,fracture density and spacing.Finally,the network model is transformed into FLAC^(3D) numerical gird based

关 键 词：灰岩含水层 渗流特征 复合网络模型 随机溶孔 

分 类 号：P642.25[天文地球—工程地质学]