Liquefaction of Saturated Sands During Cyclic Loading

Liquefaction of saturated sands was studied by means of pulsating loading triaxial tests on isotropically consolidated undrained laboratory samples. An analysis indicates that this type of test can be made to simulate idealized loading conditions on elements of soil in the field during earthquakes. The test results indicate that the danger of liquefaction of a saturated sand is determined by the following factors: (1) Void ratio; the higher the void ration the more easily liquefaction will occur. (2) Confining pressure; the lower the confining pressure the more easily liquefaction will occur, and (3) magnitude of cycle stress or strain; the larger the cyclic stress or strain the fewer the number of cycles required to induce liquefaction. Data from large shaking table experiments, and from observations of liquefaction during recent earthquakes lend qualitative support to the conclusions drawn from these laboratory cyclic loading triaxial tests.