Unsaturated Hydraulic Conductivity of Densely Compacted Gaomiaozi Bentonite Under Unconfined Conditions

Abstract:

The unsaturated permeability of compacted Gaomiaozi-bentonite was tested under unconfined conditions on the basis of the instantaneous profile method.Results show that under unconfined conditions,the unsaturated permeability of Gaomiaozi bentonite ranges from 1.0×10-12 to 1.0×10-15 m·s-1 and groups around 1.0×10-14 m·s-1,and the maximum value reaches when the specimen is saturated.Compared to the confined conditions,the unsaturated permeability under confined conditions is lower than that under unconfined conditions,and the shapes of curves between unsaturated permeability and suction under different confining conditions are different.This may because that the swelling mechanism is different under different confining conditions.

Key words:GMZ01 bentonite; unsaturated permeability; transient profile method; unconfined swelling conditions