摘要
在黄土高原水蚀风蚀交错地区,碎石的存在影响着土壤的水力学特性,因此研究土石混合介质的渗流运动对该地区的植被恢复建设具有重要的指导意义。虽然用有限元法分析地下水渗流的工作很多,但对土石混合介质而言,由于有限元法的解题规模迅速增加,其研究甚少。本模型采用子域法矩形单元,假定土石体中石块含量增加不影响土的孔隙率且石块不透水分析了土石混合介质中的渗流过程。结果表明,影响土石混合介质饱和导水率的主要因素是土石介质的含石率;石块的大小基本不影响混合介质饱和导水率;石块分布方式增加水流路径时,会影响混合介质饱和导水率。这一数值分析结论与土石体渗流问题的部分理论结果和试验结果吻合良好。本模型子域法计算效率高,结果较准确,可用于较大规模的土石混合介质渗流分析,还可推广用于土石混合介质的三维分析和多级子域法有限元技术以获得更大规模的解题效果。
In the wind-water erosion crisscross region on the Loess Plateau,the existence of stone fragments influences soil water hydraulic properties and restricts plant water efficiency. Therefore,results of this investigation for seepage flow of soil-stone mixtures could be useful to vegetation restoration in this region. Although there are a lot of researches on the seepage flow of underground water,few of them are for soil stone mixture because of its largely increasing scale of FEM solution. By employing rectangular element of sub-domain technique of finite element model and assuming that the increase of stone content in the mixture has no effects on porosity of soil and that stone is a material of no seepage,this work has analyzed the seepage flow of soil stone mixture. The computational results of this model show that the main factor which affects saturated water conductivity of soil stone mixture is the stone contents,while the stone size almost has no influence on it. However the distribution layout of stone in soll of this model is the second affecting factor for the average seepage flow velocity if the stone layout increases the length of seepage flow path. And the numerical achievements are in good agreement with some author＇s theoretical results and experimental results. The sub- domain method is of high computational performance and accuracy. And it can be used for analyzing large scale seepage flow in soil stone mixture. In addition,the method could be generalized for 3D analysis of soil stone mixture and for larger scale simulation of seepage by multi-sub-domain technique.
出处
《水土保持学报》
CSCD
北大核心
2008年第4期47-51,共5页
Journal of Soil and Water Conservation
基金
国家自然科学基金(50479063,90502006)
关键词
土石混合介质
地下水渗流
子域法
有限单元法
饱和导水率
soil stone mixture
seepage flow of underground water
sub-domain technique
finite element method
saturated water conductivity
