Synthetic Interpretation of Soil Properties Based on the Diameter Estimating Grain Size Distribution and Pore Size Indices

在本研究中，许多土壤性质可以用称为福田直径的“估计粒径分布的直径”来解释（Fukuda & Uno，1999）。这一目的的两个观点是：（1）研究强度或渗透性等动力特性与包括级配在内的土性质之间的关系;（2）尝试估算浸水时非饱和土抗剪强度的降低。（1）推导出抗剪角与用孔隙比估算粒径分布具有相关性，即使精度在5度以内，也与Fukuda的方法一样。然而，内聚不能被发现在良好的精度。另一方面，现场标准贯入试验所测得的N值也试图与任何一种土性有相关性，但没有得到很好的相关性。对于非饱和渗流问题，研究了进气量、反滤层层数等参数与福田直径的关系。（2）部分饱和土浸水后抗剪强度的降低可以通过环剪仪中应变控制试验与应力控制试验相比剪应力的降低来评价。这可以用著名的“崩溃”现象来解释。土的抗剪强度的降低程度被解释为细土和粗土之间的“压力-孔隙比”关系（所谓的e-log（p）曲线）的差异。

In this study, many kinds of soil properties could be intended to be interpreted by "the diameter estimating grain size distribution" called as Fukuda' s diameter ( Fukuda ＆ Uno, 1999 ). Two viewpoints for this aim are, ( 1 ) research for the relationships between dynamic characteristics like strength or permeability and soil properties including gradation, ( 2 ) trial to estimate the decrease in shear strength of unsaturated soils when submerged.( 1 ) The angle of shear resistance is deduced to have correlation to the diameter estimating grain size distribution with void ratio, even if the accuracy is within 5 in degree as well as Fukuda' s method. However, the cohesion could not be found in good accuracy. On the other hand, the N-values obtained by standard penetration test in site also are tried to have correlation to any soil property, but good relation was not got. As for the unsaturated seepage problems, the parameters like the air entry value and the number of filter layers are examined in the relationship with the Fukuda's diameter.( 2 ) The decrease in shear strength of partly saturated soils when submerged can be evaluated by the decrease in the shear stresses during strain-controlling test compared with stress-controlling test, which were found in the ring-shear test apparatus. This is explained in the relation to the famous 'collapse' phenomena. The grade of decrease in shear strength by the kind of soil is interpreted as the differences of 'pressure〜void ratio' relationship ( the so-called e〜log ( p ) curve ) between fine soils and coarse soils.