文献类型：期刊文献

英文题名：Experimental and Numerical Studies of the Hydraulic Properties of Three-Dimensional Fracture Networks with Spatially Distributed Apertures

作者：Huang, Na[1];Jiang, Yujing[2,3,4];Liu, Richeng[5];Li, Bo[6]

机构：[1]China Univ Petr East China, Sch Petr Engn, Qingdao 266580, Shandong, Peoples R China;[2]Nagasaki Univ, Sch Engn, 1-14 Bunkyo Machi, Nagasaki 8528521, Japan;[3]Shandong Univ Sci & Technol, State Key Lab Min Disaster Prevent & Control Cofo, Qingdao 266510, Shandong, Peoples R China;[4]Shandong Univ Sci & Technol, Minist Sci & Technol, Qingdao 266510, Shandong, Peoples R China;[5]China Univ Min & Technol, State Key Lab Geomech & Deep Underground Engn, Xuzhou 221116, Jiangsu, Peoples R China;[6]Shaoxing Univ, Ctr Rock Mech & Geohazards, Shaoxing 312000, Peoples R China

年份：2019

卷号：52

期号：11

起止页码：4731

外文期刊名：ROCK MECHANICS AND ROCK ENGINEERING

收录：SCI-EXPANDED(收录号：WOS:000495357100032)、、EI(收录号：20192407038770)、Scopus(收录号：2-s2.0-85066993259)、WOS

基金：This study has been partially funded by National Natural Science Foundation of China, China (Grant nos. 51709260, 51609136), Natural Science Foundation of Jiangsu Province, China (no. BK20170276), Japan Society for the Promotion of Science (JSPS) (no. P17382), and JSPS Grant-in-Aid for Scientific Research (no. 17H03506). These supports are gratefully acknowledged.

语种：英文

外文关键词：Fracture network; Flow test; Aperture; Channeling flow; Truncation threshold

外文摘要：Fluid flow tests on three-dimensional (3D) transparent fracture networks were performed to clarify the effect of aperture heterogeneity on the hydraulic properties of rough fractures. The five-axis machining combined with the 3D construction technique was applied to create the transparent sample, which ensures the direct visualization and quantification of flow behavior through the fractures. The effects of the anisotropic aperture on flow channeling and permeability of the fracture networks were evaluated using a developed numerical code, the validity of which has been verified by the flow test results. The numerical investigation was extended to complex 3D discrete fracture networks with large fracture densities. The results show that five-axis machining can reproduce a 3D fracture network sample with spatially distributed apertures by first machining the fracture blocks and subsequently assembling them. An obvious channeling flow in the sample was observed during the flow tests. With decreasing mean and/or increasing deviation of the aperture fields following a normal distribution, the localization of fluid flow is increasingly obvious; the main flow channels account for approximately 26-67% of the fracture planes. The ratio of permeability of the model with apertures following truncated lognormal distributions to those following complete lognormal distributions first showed remarkably increase and subsequently approached 1.0 with the increasing truncation threshold of the aperture distribution. A mathematical expression is proposed for predicting the critical truncation threshold, which is defined when the normalized permeability is equal to 0.9. The suitability of upscaling the proposed expression to complex 3D discrete fracture networks is verified, which can help to determine the proper truncation threshold when simulating a fracture aperture with lognormal distribution functions in fractured rock masses.