土与反滤层接触面上入渗角对反滤效果的影响  

The influence on the effect of filter caused by the infiltration angle of the contact surface between soil and filter

作　　者：柴鹏翔 王红雨[1,2,3] 杨佩瑶 王韵 张志龙 CHAI Pengxiang;WANG Hongyu;YANG Peiyao;WANG Yun;ZHANG Zhilong(School of Civil and Hydraulic Engineering,Ningxia University,750021 Yinchuan,China;Engineering Technology Research Center of Water-Saving and Water Resource Regulation in Ningxia,750021 Yinchuan,China;Engineering Research Center for Efficient Utilization of Modern Agricultural Water Resources in Arid Regions,Ministry of Education,750021 Yinchuan,China)

机构地区：[1]宁夏大学土木与水利工程学院,银川750021 [2]宁夏节水灌溉与水资源调控工程技术研究中心,银川750021 [3]旱区现代农业水资源高效利用教育部工程研究中心,银川750021

出　　处：《应用力学学报》2024年第1期177-187,共11页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.41962016);宁夏回族自治区重点研发计划资助项目(No.2018BFH03010)。

摘　　要：坝体内部渗流方向通常因渗流部位的不同以及上下游水位的波动而产生变化,渗透水流在被保护土与反滤层之间的接触面上的入渗角并非正交。由于筑坝土料和反滤层两者的渗透系数差异较大,渗流入渗角引起接触面水力性状发生变化,进而会影响反滤层的反滤性能。利用PFC-3D软件分别建立渗流方向与接触面呈30°、45°、60°和90°夹角的数值模型,通过模拟计算被保护土颗粒的实时侵入率及其移动进入反滤层的深度,研究了不同方向渗流作用下的接触侵蚀与反滤效果。结果表明:渗流初始阶段,不同渗流方向下被保护土颗粒的侵入率、侵入深度差距较小;随着渗流时长的增加,呈90°夹角时的侵入率比较稳定且数值较小,侵入深度和接触面处的渗流速度最小,反滤层阻挡被保护土颗粒移动的能力较强;60°、45°和30°夹角时的滤土效果依次减弱,说明渗流方向与接触面的夹角越大,反滤效果越好;利用渗流折射原理讨论了计算结果的合理性,并与有关文献的试验结果进行了对比分析,认为在堤坝等水利工程中应重视填土与反滤层之间接触面的渗流入渗角的变化,尤其是界面上小角度入渗水流对反滤效果影响较大。The seepage direction inside the dam usually changes due to the different seepage positions and the fluctuation of upstream and downstream water levels.The infiltration angle of the seepage flow on the contact surface between the protected soil and the filter is not orthogonal.Because of the great difference of permeability coefficient between the dam material and the filter,the seepage angle causes the change of hydraulic properties of the contact surface,which will affect the filter performance.In this paper,the PFC-3D is used to establish the numerical models of 30°,45°,60°and 90°between the seepage direction and the contact surface.By simulating the real-time invasion rate of the protected soil particles and the depth of their movement into the filter,the contact erosion and filter effect under the action of different seepage directions are studied.The results show that in the initial stage of seepage,the difference of invasion rate and invasion depth of protected soil particles in different seepage directions is small;with the increase of seepage time,the invasion rate at 90°is relatively stable and the value is small,the invasion depth and seepage velocity at the contact surface are the smallest,and the filter has a strong ability to block the movement of protected soil particles.The filter effect decreases at 60°,45°and 30°,indicating that the larger the angle between the seepage direction and the contact surface,the better the filter effect.The reasonableness of the calculation results is discussed by using the principle of seepage refraction,and compared and analyzed with the experimental results of relevant literature,and it is considered that the change of seepage infiltration angle at the contact surface between the fill and the filter should be paid attention to in water conservancy projects such as embankment dams,especially the fact that the small angle of infiltration flow at the interface has a greater influence on the filter effect.

关 键 词：反滤层 渗流入渗角 反滤性能 颗粒流 

分 类 号：TV44[水利工程—水工结构工程]