ONE-DIMENSIONAL VOLUME CHANGE CHARACTERISTICS OF SANDS UNDER VERY LOW CONFINING STRESSES

The paper deals with the very important problem of settlement and strength of liquefied loose sands. The laboratory test results on sands liquefied by uplift and by combined uplift pressure and impact show that the stress-strain relationship is independent of the manner of liquefaction. Interesting relations between void ratio and effective stress are presented for compression and recompression. The ratio of swell to volume-decrease coefficients is calculated for relative densities of up to 50 percent. The results obtained are compared with the authors' analytical studies estimating the effect of liquefaction in a two-layer system. It is shown that both the permeabilities and the compressibilities of these two layers have considerable influence on the development of pore water pressure in the upper stratum when the lower one is liquefied. The paper presents interesting scientific data and is of considerable value in practical application. /Author/