Seepage of aging conduits in small reservoirs by centrifuge model test

Piping is a critical failure mechanism in aging reservoirs, disrupting internal stress balance and threatening stability. In small agricultural reservoirs, aged conduits buried near the dam base are often undetected, allowing soil erosion through cracks to form voids, accelerating seepage damage. While model testing is key to studying such failures, most prior studies under standard gravity fail to replicate real stress states. This study employed centrifuge modeling to simulate three conduit configurations under dynamic water levels, refining testing methods and revealing: Pressurized seepage from upstream conduit damage alters seepage fields, exacerbates piping, and raises settlement risks; Seepage infiltrating other cracks elevates local pore pressure, softening soil and amplifying hydraulic vulnerability; Rapid water-level changes cause delayed seepage pressure response, inducing stress concentration and relaxation in high-pore-pressure zones. Repeated fluctuations fatigue dam materials, erode upstream slopes and foundations, and trigger settlement or sliding. These processes degrade soil structure, intensifying permeation risks. The findings advance understanding of seepage-piping mechanisms in dam failures.