With the rapid development of port construction,the foundation treatment of newly reclaimed silt becomes the problem which is needed to solve urgently.On the basis of field test,combining the results of each monitoring and testing,and in order to analyze the strengthening mechanism of vacuum preloading and contrast the reinforcement effect of different types of drainage plate,we study the clogging of different types of drainage plates.The testing results indicate that the connecting drainage plate and steel wire hose by new butterfly joint directly improve the transfer efficiency of vacuum degree greatly,and the vacuum degree tube to drainage plate just has small loss.During the vacuum pumping,the fine particles in soil moving toward the drainage plate with water forms the “soil column”,the pore pressure dissipation and shear strength become less with the increase of distance between drainage plate and soil.The depth range of “soil column is 1.5 m to 2.0 m based on the analysis of pore pressure dissipation and shear strength of soil.Analyzing the treatment effect of different types of drainage plates,we know that the imported membrane drainage plate is better than the the joint-ventured membrane drainage plate,and the joint-ventured is better than the ordinary membrane drainage plate.The permeability coefficient of drainage plate after treatment still meets the design requirements,and the permeability coefficient of soil reduces with the decrease of distance between the drainage plate and soil.The cause of bad treatment of soil between drainage plates is that “soil column” blocks the transfer of vacuum degree to surrounding soil.