In Situ and Laboratory Evaluation of Liquefaction Resistance of a Fine Sand.

Liquefaction is a phenomenon during which saturated cohesionless soils lose a major portion of their shear strength, and can potentially cause catastrophic failures. This study was focused on the in-situ and laboratory evaluation of liquefaction risk. Several types of penetration tests were performed. Four procedures were selected to evaluate the liquefaction potential of a number of sandy sublayers in two sites with well-documented seismic history. A new hollow cylinder equipment, which allows performing monotonic or cyclic liquefaction tests on annular soil specimens, was designed, fabricated and calibrated. The laboratory testing program included monotonic and cyclic liquefaction tests using two different testing equipment: triaxial and hollow cylinder. Effect of the main testing variables on the laboratory liquefaction potential of a fine sand, using the two equipment, were examined. The effect of the applied stress path on the monotonic and cyclic liquefaction potential of the soil was illustrated. Also, relationships between mechanisms of cyclic and monotonic liquefaction were considered, using both devices