Experimental Study on K₀ Consolidation Behavior of Recompacted Unsaturated Expansive Soil

To investigate the variation of K₀, the coefficient of lateral earth pressure at rest, with initial saturation degree (S_r) and constant radial stress (σ_rc), a series of K₀ consolidation tests were conducted on expansive soil samples under different saturation and stress conditions using a stress-path triaxial system equipped with Hall-effect transducer. The coefficient K₀ of every sample were obtained by strictly confining radial strain and evenly increasing radial stress to a given value with a slow and steady speed. The test results showed that the curve axial stress-radial stress exhibits nonlinear under small saturation degree; K₀ of samples in different saturation and stress state ranged from 0.22 to 0.72 and increased with increase of initial saturation degree and radial stress.