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Abstract Dredged fill behaves some characteristics of high water content，high compressibility and low permeability，due to the difference of formation conditions and stress history. Dredged fill behaves different permeability characteristics from natural soft clays，and it is very difficult to determine its permeability coefficient by conventional permeability test apparatus. The disadvantage of existing permeability test apparatus is overcome by GDS consolidation test apparatus，which has some great advantages for the study of nonlinear permeability characteristics and determining permeability parameter of dredged fill. Consolidation and permeability tests are performed on dredged fill in the Qianwan area of Shenzhen city by GDS consolidation test apparatus. Regression fitting analysis of four common nonlinear function relationships of permeability coefficient-void ratio for soft clays are performed；and some fitting parameters are also obtained. The obtained results indicate that：(1) After a certain consolidation pressure between 6 and 400 kPa，with the increase in consolidation pressure，a nonlinear variation in permeability coefficient of dredged fill is shown，the reduction of which is 1–2 orders of magnitude. (2) Four common nonlinear function relationships of permeability coefficient-void ratio for soft clays are conformable with dredged fill in the Qianwan area of Shenzhen city. Because of the characteristics by a simple form and best fitting，the power function relationship of permeability coefficient-void ratio is considered as a preferred nonlinear permeability relationship in the numerical analysis of large-strain and nonlinear consolidation behaviors of ultra-soft soil such as dredged fill.
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Received: 17 May 2012
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2013, Vol. 32 
