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 (ψss), initial void ratio of hosted clays (ec0) and void ratio at liquid limit of hosted clays (ecL). The roles of ψss in both the relationships of permeability coefficient of hosted clay (kv−hostedclay) versus effective vertical stress (σv′) and void ratio of hosted clay (ec−hostedclay) versus σv′ were analyzed. The results show that the permeability coefficient of reconstituted sandy clays (kv) is dominated by hosted clay (kv=kv−hostedclay). Both ψss and ec0 affect the kv of sandy clays by changing the ec−hostedclay at any given σv′. Due to the partial contacts and densified clay bridges between the sand particles (i.e. structure effects), the ec−hostedclay in sandy clays is higher than that in clays at the same σ′v. The kv−ec−hostedclay relationship of sandy clays is independent of ec0 and ψss, but is a function of ecL. The types of hosted clays affect the kv of sandy clays by changing the ecL. Based on the relationship between permeability coefficient and void ratio for the reconstituted clays, an empirical method for determining the kv is proposed and validated for sandy clays. The predicted values are almost consistent with the measured values with kv−predicted/kv−measured = 0.6–2.5.

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Keywords: Reconstituted clays, Sand fractions, Sandy clays, Consolidation-permeability coefficient tests, Void ratio of hosted clay, Permeability coefficient