EFFECTS OF OVERECONSOLIDATION ON LIQUEFACTIONSTRENGTH CHARACTERISTICS OF SAND SAMPLESUNDER K0-STRESS CONDITION

摘要

It is widely known that if sandy soil deposits are overconsolidated, their liquefaction strength increases.However, only a few studies have investigated the effects of overconsolidation by means of element teststo simulate the in-situ ground condition more correctly. In the present study, the liquefaction strengthcharacteristics of overconsolidated sand samples were investigated under K0-stress condition using ahollow cylindrical torsional shear apparatus, based on the supposition that earthquake excitations apply tothe horizontal ground. Furthermore, two methods, preloading and dewatering, were believed to simulatethe stress histories of overconsolidation. Toyoura clean sand was used as a sample. The followingbehaviors were observed in the tests; 1) The liquefaction strength was greater in the tests under K0-consolidation than under isotropic and anisotropic consolidations. 2) There is a possibility that theliquefaction strength increased more remarkably in the sandy soil deposits that were subjected to thepreloading method than to the dewatering method.