117-21 Hysteresis Effects On Soil-Gas Transport Parameters for Different Sand Size Fractions and Particle Shapes.



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Shoichiro Hamamoto1, Ken Kawamoto1, Toshiko Komatsu1 and Per Moldrup2, (1)Graduate school of Science and Engineering, Saitama University, Saitama, Japan
(2)Aalborg Univ Sohngaardsholmsvej 57 D-building, Aalborg University, Aalborg, DENMARK
Using a unified measurement system with a suction control (UMS_SC), the soil-water retention curves and gas transport parameters (gas diffusion coefficient (Dp) and air permeability (ka)) were measured for sands with different size fractions and particle shapes under drying and wetting processes. The gas transport parameters were generally higher for wetting process than those for drying process at the same soil-air content, indicating the formation of well-connected air-filled pore networks for wetting process. Higher percolation thresholds (soil-air contents where gas transport ceases due to interconnected water films) were observed for ka measurements as compared to Dp measurements under both drying and wetting processes. Sand particle size and shape effects on the hysteretic behavior of both soil-gas transport parameters (ka and Dp) will be further investigated and presented in this study.
See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)