Infiltration resistance of hydrophobic soil slopes under extreme rainfall: centrifuge model tests

초록

The increasing frequency of extreme rainfall necessitates slope protection methods that directly regulate infiltration. This study proposes engineered hydrophobicity as a delay-based infiltration control mechanism. Centrifuge model tests were conducted to evaluate slopes containing hydro-phobically treated soil layers under prototype-scale rainfall (90 mm/h). Compared to untreated slopes, the hydrophobic layers delayed wetting-front progression and pore-water pressure buildup. Although thicker hydrophobic layers increased infiltration delay, they also reduced post-rainfall drainage efficiency and promoted water accumulation near the lower slope. Comparative tests using silica sand and recycled fine aggregates demonstrated the applicability of the method to dif-ferent soil types, with recycled materials providing comparable resistance. These results indicate that engineered hydrophobic soils can function as delay-based infiltration-control layers under extreme rainfall conditions.

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