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Rules‐of‐Thumb for Predicting Air‐Entry Value of Disturbed Sands from Particle Size
Author(s) -
Sakaki Toshihiro,
Komatsu Mitsuru,
Takahashi Manabu
Publication year - 2014
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2013.06.0237n
Subject(s) - particle size , mineralogy , particle (ecology) , particle size distribution , exponent , materials science , analytical chemistry (journal) , chemistry , geology , chromatography , oceanography , linguistics , philosophy
With the goal of finding empirical direct relationships between the air‐entry values (AEV) and characteristic particle diameters (i.e., d 10 , d 20 , d 30 ,… d 90 ,) determined from the particle‐size distribution, we examined the AEV values for a variety of disturbed sands. It was found that the AEVs were, in general, strongly correlated to the characteristic diameters. The correlation was more distinct for uniform sands with uniformity coefficient of 2 or smaller. For those with larger uniformity coefficient values, the AEVs were highly correlated to smaller characteristic particle sizes d 10 to d 50 but less with larger characteristic particle sizes, d 60 to d 90 . For all the sands examined in this study, the AEVs showed the least scatter when plotted against d 30 . The large particles do not necessarily control the AEVs because the pores between the large particles are often filled with smaller particles. The following best‐fit power functions with respect to the frequently used characteristic particle diameters were found to have high r 2 values; AEV = 8.2 d 30 −0.99 and AEV = 9.5 d 50 −1.05 (with AEV in cm and d in mm). The exponent close to ‐1 in both relationships confirms a strong “inverse” proportionality. The effective pore diameter, d e , estimated from the AEVs agreed closely with the mean pore diameters measured with mercury porosimetry and X‐ray micro‐tomography. All these findings suggest that the AEVs are strongly controlled by the particle sizes which determine the mean pore size, and that the capillary rise theory is applicable in terms of the effective pore diameter. Finally, easy‐to‐implement rule‐of‐thumb expressions, AEV [cm] = 8/ d 30 [mm] and AEV [cm] = 10/ d 50 [mm] were proposed with some limitations for a quick but reasonably accurate prediction of the AEV.