Interrelation between compressibility and permeability of reconstituted sandy clays with different sand fractions

Abstract

It has been well recognized that sand particles significantly affect the mechanical properties of reconstituted sandy clays, including the hosted clay and sand particles. However, interrelation between the permeability and compressibility of reconstituted sandy clays by considering the structural effects of sand particles is still rarely reported. For this, a series of consolidation-permeability coefficient tests were conducted on reconstituted sandy clays with different sand fractions (), initial void ratio of hosted clays () and void ratio at liquid limit of hosted clays (). The roles of in both the relationships of permeability coefficient of hosted clay () versus effective vertical stress () and void ratio of hosted clay () versus were analyzed. The results show that the permeability coefficient of reconstituted sandy clays () is dominated by hosted clay (). Both and affect the of sandy clays by changing the at any given . Due to the partial contacts and densified clay bridges between the sand particles (i.e. structure effects), the in sandy clays is higher than that in clays at the same σ′v. The relationship of sandy clays is independent of and , but is a function of . The types of hosted clays affect the of sandy clays by changing the . Based on the relationship between permeability coefficient and void ratio for the reconstituted clays, an empirical method for determining the is proposed and validated for sandy clays. The predicted values are almost consistent with the measured values with = 0.6 - 2.5.