The effect of isotropic preloading on static liquefaction of sandy soils

Abstract

Despite the fact that liquefaction phenomenon has been studied for decades, the effect of isotropic preloading on static liquefaction is still an issue not fully understood. This paper presents the results of an experimental program using triaxial apparatus on the influence of monotonic preloading on the liquefaction resistance of Fontainebleau sand and mixture of sand-illite. About twenty loose soils samples had been prepared by moist tamping and consolidated at different overconsolidation ratios (OCR). Results show a marked increase of the static liquefaction strength with increasing values of OCR considered. The effect is more pronounced up to a value of OCR = 2 and less noticeable at higher OCR. At normal consolidation ratio (OCR = 1), complete static liquefaction occurs, however, at higher overconsolidation ratio, the complete static liquefaction changes in temporary liquefaction. Moreover, at the highest overconsolidation ratios (OCR = 5, 6, 8, 10), the values of peak deviator are almost unchanged.