Effect of surface soils with different hydrophobicities on infiltration

• Main Author: Lim, Ye Xun
• Other Authors: Leong Eng Choon
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/150524
• Institution: Nanyang Technological University

Soil hydrophobicity has been frequently investigated as it occurred naturally and can be used to stabilize the soil below or prevent contamination. In this research, the effect of varying degree of soil hydrophobicity was studied to observe its effect on the rate of infiltration. An infiltration column experiment was conducted with fine sand and fine sand with different degree of hydrophobicity overlying coarse sand. The pressure head on top of the fine sand was kept at 2 cm for all tests. The measured results of pore-water pressure and volumetric water content were compared to the simulated results of Hydrus 1-D. The experimental results shows that the use of a hydrophobic fine sand mixture decreases the rate of infiltration, and a higher degree of hydrophobicity results in a slower infiltration into the underlying coarse sand. Hydrus 1-D performed well in simulating the experimental results. Sensitivity tests performed showed that Hydrus 1-D gave a better match to the experimental results when the SWCC parameters of the wetting curve of the fine sand were used as compared to the drying curve obtained from Tempe cell test. The saturated hydraulic conductivity was also found to have a big influence on the pore-water pressure as compared to the volumetric water content.