无黏性粗粒土强度的三轴尺寸效应

Size Effects on the Shear Strength of the Cohesionless Coarse-Grained Soils under the Triaxial Compression Condition

为研究粗粒土抗剪强度的三轴尺寸效应,进行了相同试样尺寸条件下不同最大粒径无黏性粗粒土的三轴压缩试验。试样直径101 mm,试验土料最大粒径分别为2 mm,5 mm,10 mm,20mm,40 mm,且具有自相似分形结构以避免几何填充特性对尺寸效应的影响。试验结果表明,随着最大粒径增大,无黏性粗粒土的抗剪强度增大,线性和非线性抗剪强度参数皆有增大的趋势;当最大粒径大于试样直径的1/5时,三轴试验中无黏性粗粒土的抗剪强度具有明显的尺寸效应。

To study the size effects on the shear strength of the cohesionless coarse-grained soils,the triaxial compression tests with the same specimen size are carried out for cohesionless coarse-grained soils with different maximum grain sizes. The diameter of specimen is 101 mm and the maximum particle diameters are 2 mm,5 mm,10 mm,20 mm and 40 mm,respectively. To refrain from the effects of the void structure on the size effect,the cohesionless coarse-grained soils with self-similar fractal structure in mass are used. The test results show that the shear strength,the linear and nonlinear strength parameters increase with the increase of the maximum grain size. There are apparently size effects on the shear strength for the cohesionless coarse-grained soils under the triaxial compression condition when the maximum grain size is greater than the 1 /5 of the specimen diameter.