In recent years,with the advantages of water saving,high efficiency and low cost,the self-suction dredging pipeline has gradually become one of the main measures for reservoir dredging projects.However,when the soil particles are fine and the silt has been deposited for a long time,its dredging effect decreases obviously.In order to explore the mechanism of breaking soil and influencing factors of sediment in-cipience,model test method was adopted in this paper.A cohesive sediment sample was prepared by negative pressure consolidation,and then the vertical submerged jet experiment with different jet velocity,jet spray nozzle size and jet target distance was carried out.The experi-mental results show that the erosion breaking mechanism of the cohesive soil sample is quite different from that of the non-cohesive soil due to the existence of viscosity.The development process of the scour hole has certain randomness and self-similarity.The erosion efficiency of the jet flow is proportional to the jet velocity and the Jet spray nozzle size,and inversely proportional to the jet standoff distance.At the same time,the jet target distance has the most obvious influence to the shape of scour holes.
维普
万方数据