NONLINEAR PERMEABILITY AND PARAMETER DETERMINATION FOR DREDGED FILL BASED ON GDS CONSOLIDATION APPARATUS
ZHANG Ming1，2，JIANG Minmin3，ZHAO Youming2
(1. School of Civil Engineering，Henan Institute of Engineering，Zhengzhou，Henan 451191，China；2. China Academy of Railway Sciences，Beijing 100081，China；3. School of Civil and Architecture，Henan University of Technology，
Zhengzhou，Henan 450052，China)
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.
NARASIMHA RAJU P S R，PANDIAN N S，NAGARAJ T S. Determination of the coefficient of consolidation from independent measurement of permeability and compressibility[J]. Proceedings of the Institution of Civil Engineers—Geotechnical Engineering，1997，125(4)：224-229.
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2013, Vol. 32 
