Evolution Law of Loose Accumulation Layer Structure under the Action of Seepage Piping
To reveal the evolution law of loose accumulation layer structure under the action of seepage piping.Based on the parti-cle pore scale fluid-solid coupling method,seepage piping simulation experiments were conducted on loose accumulations with dense,medium dense,and loose structures,respectively.The structural evolution characteristics of particle migration,particle loss,indirect particle contact chain evolution,and skeleton deformation in the loose accumulation layer under the action of seepage piping were ana-lyzed at the mesoscale.The results show that the seepage piping is mainly dominated by fine particle migration,and there is a local"blockage"phenomenon,while the rock particles only accumulate freely after the fine particles migrate and become empty.The migration of fine particles has an obvious"particle accumulation"phenomenon,mainly concentrated at the outlet boundary,characterized by"more up and less down".Meanwhile,the porosity changes at the same location during the development of seepage piping are highly similar and become more significant as the structure becomes more porous.During the development of piping,the contact between rock particles bears the main stress transmission,and the essence of force chain evolution is the change of the stress transmission structure inside the packing.Besides,both the subsidence amount and the volumetric strain gradually increase at any time,showing a trend of rapid increase at first,and then tending to be stable.As the initial seepage velocity increases,the stable time gradually advances.The study can provide some reference for understanding the evolution law of seepage piping structures in loose accumulation layers from a mesoscopic perspective.
万方数据
维普
