摘要
采用自主研制的圆柱形渗流仪及水平渗流装置,开展了粉砂竖向和水平向的渗流试验,获取了两种渗流方向下粉砂的临界水力梯度及其渗透变形特性。在级配、密度、孔隙大小等影响因素相同的前提下,粉砂竖向渗流的临界水力梯度比水平向高出近44%,水平向渗流作用一般高于竖向。基于室内试验成果,采用离散元与计算流体力学耦合的细观力学模型,对粉砂在竖向和水平向的渗流情况进行分析和模拟。结果表明,粉砂的渗透变形拐点与模型试验结果吻合,水平渗流和竖向渗流分别在水力梯度i=0.8,0.4时出现颗粒簇的流失,在水力梯度分别为1.0和0.5时发生整体渗透破坏。
The influence of seepage direction on the silt permeability are studied.The vertical and horizontal seepage tests of silty sand are carried out by using the self-designed devices.The critical gradient and deformation characteristics of silt under two different seepage directions are obtained in the tests.When the other influencing factors such as gradation,density and pore size are the same,the vertical hydraulic gradient of horizontal seepage of silt is generally 44%higher than the critical one,and the horizontal seepage is generally higher than the vertical one.The data can be used for design of seepage control of the silt.Based on the indoor model tests,the micro-mechanical model is used to analyze and simulate the seepage behavior of the silt under vertical and horizontal directions.The hydraulic gradients of the two seepage directions calculated by numerical model are consistent with the test ones.The loss of particle clusters occurs in horizontal and vertical seepages at hydraulic gradients of 0.8 and 0.4,respectively.The research results may provide a theoretical basis for the design of seepage control in water conservancy and hydropower projects with silt layer.
作者
张灿虹
钱亚俊
钟启明
王保田
ZHANG Can-hong;QIAN Ya-jun;ZHONG Qi-ming;WANG Bao-tian(Nanjing Vocational University of Industry Technology,Nanjing 210023,China;Geotechnical Engineering Department,Nanjing Hydraulic Research Institute,Nanjing 210024,China;Hohai University,Nanjing 210098,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2020年第S02期163-167,共5页
Chinese Journal of Geotechnical Engineering
基金
江苏省高校自然科学研究项目(19KJB560016)
南京工业职业技术学院人才引进启动基金项目(YK19-02-02)
国家自然科学基金青年基金项目(51809182)
关键词
渗流方向
粉砂土
渗透试验
流固耦合
seepage direction
silty sand soil
permeability test
fluid-solid coupling