Experimental Study On Bucket Foundation And Plug In Silty Sand During Penetration By Suction

The thesis is the initial research content of the project "Bucket Foundation and Unstability Mechanism Research Influenced by Bucket foundation on Silty.Sand Seabed", which is supported by the national natural science fund. It mainly carry about the research of seepage gradient in the process of suction penetration and unstability mechanism of silty sand in the bucket foundation, and it also discuss and analyze the penetration effect of bucket foundation of the different ratio size.The penetration effect of the different ratio size in the process of penetration is studied and analyzed according to the result of experiment.The calculating method of critical seepage gradient is brought forward through the mechanics analysis of the soil unit. Seepage gradient is divided into three different distributing style, through the analysis of data from sensors, on the basis of the position of the end of bucket foundation and the maximum seepage gradient.The conclusions are drawn that the soil body's failure style at the end of bucket foundation is shear failure under condition of the high seepage gradient;Penetration resistance is mainly the resistance of the end of bucket foundation, because friction can be omit according to calculation, the bucket foundation of the thicker wall reduces more resistance in the soil body.The five reason of the formation and development of the plug is considered , and the rheology of soil body in the plastic deformation area is especially pointed out; The statistic model is built in order to calculate the plug's length, and the practical significance of the model parameters is given out. It plays an important role on predicting the length of the plug in the process of penetration.