Experimental evaluation of the drainage performance of wicking geotextiles in GRS retaining walls subjected to rainfall

초록

This study evaluated the drainage performance of a wicking geotextile (W-GT) through reduced-scale model tests to address rainfall-induced instability in geosynthetic-reinforced soil (GRS) retaining walls. The results indicate that W-GT effectively mitigates the capillary barrier effect at the soil–geotextile interface and forms in-plane drainage pathways even under unsaturated conditions. A comparative assessment of two key design variables—installation depth and number of layers—showed that installation depth governs drainage performance. Placing W-GT at the lowest layer produced a drainage efficiency (DE) approximately 11.7 times higher than that achieved by increasing the number of layers alone. In contrast, increasing the number of W-GT layers primarily enhanced the storage reduction efficiency (SRE) within the backfill, with three layers improving SRE by up to 78% relative to a single layer. Overall, these findings suggest that, for practical design, prioritizing a hydraulically effective installation depth that maximizes DE is more effective and economical than simply increasing the number of layers.

키워드