基于离散元法的接触冲刷影响因素研究
|
摘要
成层土间容易发生接触冲刷破坏,对水工建筑物的安全运行有不利影响。为此探讨了粗层孔隙率、粗层颗粒形状和剪切位移对接触冲刷的影响,采用离散元法对成层无粘性土进行了接触冲刷数值模拟,得到以下结论:粗土层孔隙率的增加对土层抗渗流冲刷不利,对于D10/d10比值为10的土层,当粗土层的孔隙率相对较大时,在一定的渗流压力作用下,试样的渗透流速在初始阶段会有一定减小,随着细颗粒流失比的不断增大,渗透流速也随之增大,土层结构发生较大改变,也会发生接触冲刷破坏,在工程实践中应该引起一定的重视;当粗层颗粒形状为非球形时,细土层颗粒流失比减小,土层抗冲刷破坏能力有所提高;剪切变形后试样中粗土层孔隙率会有一定增大,孔隙结构也会发生改变,细土层颗粒流失比增大,加剧了土层发生接触冲刷破坏的风险。
Contact erosion easily occurs in soil layers,which influences the safety of hydraulic structures. The effects of several factors on contact erosion,such as porosity of coarse layer,particle shape of coarse layer and shear deformation,were explored based on discrete element method for cohesionless soil layers. The results show that the increasing porosity of coarse layer is bad for the resistance of contact erosion. When D10/d10 of the soil layers is about equal to 10,contact erosion may occur if the porosity of coarse layer is large enough. The flow velocity of numerical sample first slightly decreases at the beginning of contact erosion. With the continuous increase in the erosion ratio of fine particles,the flow velocity gradually increases and the soil structure has an obvious change,which is bad for the seepage resistance of contact erosion and should be paid more attention in practice. When the soil particle shape of coarse layer is non-spherical,the erosion ratio of fine particles decreases and the seepage resistance of contact erosion is higher. For numerical samples under shear deformation,the porosity of coarse layer increases and the pore structure changes,so more fine particles are eroded and flow out through the pores of coarse layer during contact erosion simulation,which increases the risk of seepage failure.
Contact erosion easily occurs in soil layers,which influences the safety of hydraulic structures. The effects of several factors on contact erosion,such as porosity of coarse layer,particle shape of coarse layer and shear deformation,were explored based on discrete element method for cohesionless soil layers. The results show that the increasing porosity of coarse layer is bad for the resistance of contact erosion. When D10/d10 of the soil layers is about equal to 10,contact erosion may occur if the porosity of coarse layer is large enough. The flow velocity of numerical sample first slightly decreases at the beginning of contact erosion. With the continuous increase in the erosion ratio of fine particles,the flow velocity gradually increases and the soil structure has an obvious change,which is bad for the seepage resistance of contact erosion and should be paid more attention in practice. When the soil particle shape of coarse layer is non-spherical,the erosion ratio of fine particles decreases and the seepage resistance of contact erosion is higher. For numerical samples under shear deformation,the porosity of coarse layer increases and the pore structure changes,so more fine particles are eroded and flow out through the pores of coarse layer during contact erosion simulation,which increases the risk of seepage failure.
引文
[1]刘杰,丁留谦,缪良娟.沟后面板砂砾石坝溃坝机理模型试验研究[J].水利学报,1998,29(11):69-75.(Liu Jie,Ding Liuqian,Miao Liangjuan.Model test for dam breach of Gouhou concrete face sandy gravel dam[J].Journal of Hydraulic Engineering,1998,29(11):69-75.(in Chinese))
[2]刘杰,谢定松,崔亦昊.江河大堤堤基砂砾石层管涌破坏危害性试验研究[J].岩土工程学报,2009,31(8):1188-1191.(Liu Jie,Xie Dingsong,Cui Yihao.Destructive tests on piping failure of sandy gravel layer of river dikes[J].Journal of Geotechnical Engineering,2009,31(8):1188-1191.(in Chinese))
[3]刘杰.无黏性土层之间渗流接触冲刷机理试验研究[J].水利水电科技进展,2011,31(3):27-30.(Liu Jie.Mechanism of seepage contact scour between cohesionless soil layers[J].Advances in Science and Technology of Water Resources,2011,31(3):27-30.(in Chinese))
[4]陈建生,刘建刚,焦月红.接触冲刷发展过程模拟研究[J].中国工程科学,2003,5(7):33-39.(Chen Jiansheng,Liu Jiangang,Jiao Yuehong.Simulation study on the contact scouring development between underground layers[J].Engineering Science,2003,5(7):33-39.(in Chinese))
[5]邓伟杰.土石坝接触冲刷试验与分析研究[D].南京:河海大学,2008.(Deng Weijie.Experiment and analysis of the contact scouring of earth-rock dam[D].Nanjing:Hohai University,2008.(in Chinese))
[6]陈群,彭君,朱分清.砂砾石与砂接触冲刷试验研究[J].岩土力学,2016,37(增1):295-300.(Chen Qun,Peng Jun,Zhu Fenqing.Experimental study of contact scouring between sandy gravel and sand[J].Rock and Soil Mechanics,2016,37(Supp.1):295-300.(in Chinese))
[7]朱亚军,彭君,陈群.砂砾石与黏土的接触冲刷试验研究[J].岩土工程学报,2016,38(增2):92-97.(Zhu Yajun,Peng Jun,Chen Qun.Contact scouring tests on sandy gravel and cohesive soil[J].Chinese Journal of Geotechnical Engineering,2016,38(Supp.2):92-97.(in Chinese))
[8]Guidoux C,Faure Y H,Beguin R,et al.Contact erosion at the interface between granular filter and various base soils with tangential flow[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(5):741-750.
[9]Beguin R,Philippe P,Faure Y H.Experimental study of contact erosion at a granular interface[J].Springer Series in Geomechanics and Geoengineering,2011,11:131-136.
[10]Beguin R,Philippe P,Faure Y H.Pore-scale flow measurements at the interface between a sandy layer and a model porous medium:application to statistical modeling of contact erosion[J].Journal of Hydraulic Engineering,2013,139(1):1-11.
[11]中华人民共和国国家发展和改革委员会.碾压式土石坝设计规范(DL/T 5395-2007)[S].北京:中国电力出版社,2008.(National Development and Reform Commission.Design specification for rolled earth-rock fill dams(DL/T 5395-2007)[S].Beijing:China Electric Power Press,2008.(in Chinese))
[12]姚志雄.三维离散元法解析砂型泥石流细观运动特征研究[J].地下空间与工程学报,2017,13(5):1414-1423.(Yao Zhixiong.Analysis on mesoscopic movement characteristic of sandy debris flow by 3Ddiscrete element[J].Chinese Journal of Underground Space and Engineering,2017,13(5):1414-1423.(in Chinese))
[13]Shamy U E,Aydin F.Multiscale modeling of floodinduced piping in river levees[J].Journal of Geotechnical and Geoenvironmental Engineering,2008,134(9):1385-1398.
[14]Huang Q F,Zhan M L,Sheng J C,et al.Investigation of fluid flow-induced particle migration in granular filters using a DEM-CFD method[J].Journal ofHydrodynamics,2014,26(3):406-415.
[15]Bonelli S.Erosion of geomaterials[M].New York:John Wiley and Sons Inc,2012
[16]雷红军.高土石坝粘性土大剪切变形条件下渗透特性研究[D].北京:清华大学,2010.(Lei Hongjun.Astudy on seepage characteristics of clayey soil of high earth-rockfill dam with large shear deformation[D].Beijing:Tsinghua University,2010.(in Chinese))
[17]吴越,杨仲轩,徐长节.初始组构各向异性对砂土力学特性及临界状态的影响[J].岩土力学,2016,37(9):2569-2576.(Wu Yue,Yang Zhongxuan,Xu Changjie.Effects of initial fabric anisotropy on mechanical behavior and critical state of granular soil[J].Rock and Soil Mechanics,2016,37(9):2569-2576.(in Chinese))
[18]蒋明镜,付昌,刘静德,等.不同沉积方向各向异性结构性砂土离散元力学特性分析[J].岩土工程学报,2016,38(1):138-145.(Jiang Mingjing,Fu Chang,Liu Jingde,et al.DEM simulation of anisotropic structured sand with different deposit directions[J].Chinese Journal of Geotechnical Engineering,2016,38(1):138-145.(in Chinese))
[2]刘杰,谢定松,崔亦昊.江河大堤堤基砂砾石层管涌破坏危害性试验研究[J].岩土工程学报,2009,31(8):1188-1191.(Liu Jie,Xie Dingsong,Cui Yihao.Destructive tests on piping failure of sandy gravel layer of river dikes[J].Journal of Geotechnical Engineering,2009,31(8):1188-1191.(in Chinese))
[3]刘杰.无黏性土层之间渗流接触冲刷机理试验研究[J].水利水电科技进展,2011,31(3):27-30.(Liu Jie.Mechanism of seepage contact scour between cohesionless soil layers[J].Advances in Science and Technology of Water Resources,2011,31(3):27-30.(in Chinese))
[4]陈建生,刘建刚,焦月红.接触冲刷发展过程模拟研究[J].中国工程科学,2003,5(7):33-39.(Chen Jiansheng,Liu Jiangang,Jiao Yuehong.Simulation study on the contact scouring development between underground layers[J].Engineering Science,2003,5(7):33-39.(in Chinese))
[5]邓伟杰.土石坝接触冲刷试验与分析研究[D].南京:河海大学,2008.(Deng Weijie.Experiment and analysis of the contact scouring of earth-rock dam[D].Nanjing:Hohai University,2008.(in Chinese))
[6]陈群,彭君,朱分清.砂砾石与砂接触冲刷试验研究[J].岩土力学,2016,37(增1):295-300.(Chen Qun,Peng Jun,Zhu Fenqing.Experimental study of contact scouring between sandy gravel and sand[J].Rock and Soil Mechanics,2016,37(Supp.1):295-300.(in Chinese))
[7]朱亚军,彭君,陈群.砂砾石与黏土的接触冲刷试验研究[J].岩土工程学报,2016,38(增2):92-97.(Zhu Yajun,Peng Jun,Chen Qun.Contact scouring tests on sandy gravel and cohesive soil[J].Chinese Journal of Geotechnical Engineering,2016,38(Supp.2):92-97.(in Chinese))
[8]Guidoux C,Faure Y H,Beguin R,et al.Contact erosion at the interface between granular filter and various base soils with tangential flow[J].Journal of Geotechnical and Geoenvironmental Engineering,2010,136(5):741-750.
[9]Beguin R,Philippe P,Faure Y H.Experimental study of contact erosion at a granular interface[J].Springer Series in Geomechanics and Geoengineering,2011,11:131-136.
[10]Beguin R,Philippe P,Faure Y H.Pore-scale flow measurements at the interface between a sandy layer and a model porous medium:application to statistical modeling of contact erosion[J].Journal of Hydraulic Engineering,2013,139(1):1-11.
[11]中华人民共和国国家发展和改革委员会.碾压式土石坝设计规范(DL/T 5395-2007)[S].北京:中国电力出版社,2008.(National Development and Reform Commission.Design specification for rolled earth-rock fill dams(DL/T 5395-2007)[S].Beijing:China Electric Power Press,2008.(in Chinese))
[12]姚志雄.三维离散元法解析砂型泥石流细观运动特征研究[J].地下空间与工程学报,2017,13(5):1414-1423.(Yao Zhixiong.Analysis on mesoscopic movement characteristic of sandy debris flow by 3Ddiscrete element[J].Chinese Journal of Underground Space and Engineering,2017,13(5):1414-1423.(in Chinese))
[13]Shamy U E,Aydin F.Multiscale modeling of floodinduced piping in river levees[J].Journal of Geotechnical and Geoenvironmental Engineering,2008,134(9):1385-1398.
[14]Huang Q F,Zhan M L,Sheng J C,et al.Investigation of fluid flow-induced particle migration in granular filters using a DEM-CFD method[J].Journal ofHydrodynamics,2014,26(3):406-415.
[15]Bonelli S.Erosion of geomaterials[M].New York:John Wiley and Sons Inc,2012
[16]雷红军.高土石坝粘性土大剪切变形条件下渗透特性研究[D].北京:清华大学,2010.(Lei Hongjun.Astudy on seepage characteristics of clayey soil of high earth-rockfill dam with large shear deformation[D].Beijing:Tsinghua University,2010.(in Chinese))
[17]吴越,杨仲轩,徐长节.初始组构各向异性对砂土力学特性及临界状态的影响[J].岩土力学,2016,37(9):2569-2576.(Wu Yue,Yang Zhongxuan,Xu Changjie.Effects of initial fabric anisotropy on mechanical behavior and critical state of granular soil[J].Rock and Soil Mechanics,2016,37(9):2569-2576.(in Chinese))
[18]蒋明镜,付昌,刘静德,等.不同沉积方向各向异性结构性砂土离散元力学特性分析[J].岩土工程学报,2016,38(1):138-145.(Jiang Mingjing,Fu Chang,Liu Jingde,et al.DEM simulation of anisotropic structured sand with different deposit directions[J].Chinese Journal of Geotechnical Engineering,2016,38(1):138-145.(in Chinese))