Abstract：Sand fluidization induced by leakage from water supply pipelines is a critical mechanism contributing to subsurface voids and ground collapse. Most existing studies have focused on fully saturated sands, with limited exploration of unsaturated conditions. This study employs model tests to investigate the fluidization behavior of sand under varying initial submerged water levels. The results reveal a distinct secondary expansion of fluidized cavities within unsaturated sand beds. A hydraulic criterion for complete fluidization under unsaturated conditions is proposed. Empirical relationships for the hydraulic gradient at different saturation levels are established based on pore water pressure measurements. A theoretical formula for the critical flow rate necessary for complete sand fluidization, derived from the momentum theorem, is developed and validated through experiments. The findings demonstrate that the critical flow rate is significantly influenced by the initial submerged water level. Additionally, capillary-induced matric suction inhibits the initiation and progression of sand fluidization under unsaturated conditions.
林存刚1，2，3，4，秦家贵1，陶旭光5，刘志军6，丁 智7. 不同饱和状态砂土渗漏流化特性及水力准则[J]. 岩石力学与工程学报, 2025, 44(9): 2500-2514.
LIN Cungang1, 2, 3, 4, QIN Jiagui1, TAO Xuguang5, LIU Zhijun6, DING Zhi7. Fluidization characteristics and hydraulic criteria of sand under varying saturation states induced by leakage. , 2025, 44(9): 2500-2514.
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2025, Vol. 44 
