Experimental study of the effect of microstructure on the permeability of saturated soft clays

Abstract

The effect of microstructure on the permeability of two saturated marine clays was studied through a series of falling head permeability tests and mercury intrusion porosimetry (MIP) tests. The key findings from this experimental study include the following results: (1) The permeability of undisturbed specimens is larger than that of reconstituted specimens at the same void ratio due to different soil fabrics, i.e., the pore size distributions (PSDs), even though they have the similar variation law in the permeability versus void ratio. (2) Different permeabilities of undisturbed and reconstituted specimens at the same void ratio are mainly caused by the difference in void ratio of macro-pores based on the MIP test results. (3) A high relevant relation between Ck (Ck is the permeability change index) and e*10, can be found by normalizing the measured data both on undisturbed or reconstituted specimens. Hence, the reference void ratio e*10, can be used as a reasonable parameter to identify the effect of soil fabric on the permeability of saturated soft clays.