ABSTRACT
Soil liquefaction is one of the most complex phenomena characterised by the rapid loss of the strength and stiffness of soil. In the laboratory, the liquefaction resistance can be assessed by different testing procedures, involving axisymmetric and plain strain conditions. This paper addresses an experimental comparison between the results of cyclic triaxial and cyclic direct simple shear testing. The tests were conducted using a historically liquefiable sand from the city centre of Lisbon, denominated as TP-Lisbon sand. Findings showed a higher liquefaction resistance for axisymmetric conditions (cyclic triaxial tests) than plane strain conditions (direct simple shear tests). Therefore, a method to transform the results derived from either cyclic triaxial or direct simple shear is proposed. This method provides a reliable prediction of liquefaction resistance derived inversion and rotation of principal stresses in a single approach.
