Laboratory assessment of saturation and sample molding effects on shear resistance and mechanical characteristics of sandy soil

In order to evaluate shear resistance characteristics of sand, which has previously experienced liquefaction, two series of drained and undrained monotonic triaxial compression tests on medium dense sand were carried out. In the first test series, the influence of the specimen preparation method and confining pressure has been studied. It was found that there was a marked difference in the behavior even though the density and stress conditions were identical. The conclusion was that the soil fabric was responsible for this result. In the second series of tests, the saturation influence on the shear resistance of the sand was examined. The results showed that the decrease in Skempton's pore pressure coefficient B improves the shear resistance and increases the friction angle of the sand.