宽级配粗粒土渗透试验尺寸效应及边壁效应研究

Study of size and wall effects in seepage test of broadly graded coarse materials

尺寸效应及边壁效应是粗粒土渗透试验中的常见问题。采用一系列渗透试验,研究了粗粒料渗透试验的尺寸效应规律,提出了渗透仪尺寸的选择原则,即渗透仪直径与试验材料d85之比值不宜小于6;研究了不同的超径颗粒处理方法对渗透试验成果的影响,分析表明,对超径颗粒可以适度采用等量替代法,不宜采用相似级配法;研究了仪器护壁处理厚度对仪器边壁处理效果的影响,提出了确定护壁处理厚度的建议。

Size effect and wall effect are very common problems in seepage test of broadly graded coarse materials.A series of seepage tests are performed.The size effect is analyzed and the principle for apparatus size selection is studied.It is proposed that the apparatus diameter is not less than 6 times of test material＇s d85.Effects of different methods for treating grains of size over limit on permeability test results are discussed.It is concluded that carefully taking equivalently alternative method is acceptable;while scale method is not.The wall effect is discussed and the thickness of wall treatment layer is proposed.