摘要
针对渗透性尺寸效应涉及的影响因素众多、导致其演变规律及主控因素还不甚明了的问题,基于Comsol数值模拟软件,开展岩体单裂隙渗透性尺寸效应的数值模拟研究。建立开度服从正态分布的大尺寸岩体单裂隙模型(试样尺寸为5 m×5 m),在同一大尺寸试样上选取系列尺寸岩体单裂隙试样,并开展相应尺寸岩体单裂隙的渗透数值试验,观察岩体单裂隙渗透性随尺寸变化的演变规律。通过改变粗糙度、水力梯度和裂隙开度等参数,研究不同因素对岩体单裂隙渗透性尺寸效应的影响,确定其中的主控因素。数值模拟结果表明:岩体单裂隙的渗透性随试样尺寸的增大而增大,随后趋于一稳定值,其对应的试样尺寸即为临界尺寸;临界尺寸随粗糙度的增加、水力梯度的降低、裂隙开度的减小而增大;相较于粗糙度和水力梯度,裂隙开度对岩体单裂隙渗透性尺寸效应的影响更显著。
Aiming at the problem of that the influence factors related to the size effect of permeability are numerous,thus its evolution law and relevant dominant factors are not so clear,a numerical simulation on the size effect of the permeability of single rock fracture is carried out based on Comsol numerical simulation software.Firstly,a single large-size rock fracture model(the sample size is 5 m×5 m)with the fracture aperture subjected to normal distribution is established,and then the samples of rock fractures with serial sizes are selected from the sample with the same size;from which the numerical experiment on the permeability of the corresponding sized single rock fracture is made for observing the evolution law of its permeability along with the change of the size.Through changing parameters,such as roughness,hydraulic gradient,fracture aperture,etc.,the influences from different factors on the sizer effect of the permeability are studied,so as to determine the dominant factors therein.The numerical simulation result shows that the permeability of single rock fracture is increased along with the increase of the sample size and subsequently trends to be stable,for which the corresponding sample size is just the critical size.Moreover,the critical size is increased along with increase of roughness,decrease of hydraulic gradient and decrease of fracture aperture.Furthermore,the influence from fracture aperture on the size effect of the permeability of single rock fracture is more significant,if compared with roughness and hydraulic gradient.
作者
高超
钟振
胡云进
鲍如意
GAO Chao;ZHONG Zhen;HU Yunjin;BAO Ruyi(College of Civil Engineering,Shaoxing University,Shaoxing312000,Zhejiang,China;Center of Rock Mechanics and Geohazards,Shaoxing University,Shaoxing312000,Zhejiang,China)
出处
《水利水电技术》
CSCD
北大核心
2018年第12期148-153,共6页
Water Resources and Hydropower Engineering
基金
国家自然科学基金项目(51509154)
浙江省自然科学基金项目(LQ16E090002)
浙江省科技厅公益技术研究项目(2015C31134)
关键词
岩体单裂隙
裂隙开度
粗糙度
尺寸效应
临界尺寸
表征单元体
渗流力学
岩石力学
single rock fracture
fracture aperture
roughness
size effect
critical size
representation unit
seepage mecha-nics
rock mechanics
