Abstract:Acquiring large-scale undisturbed samples of natural loess is very difficult due to its special original structure.Therefore,no data or documents are available of shaking-table testing on saturated samples of undisturbed loess soil around the world.In the present study,we address the problems of preparing large-scale undisturbed loess samples in the field and conducting research on the liquefaction features of saturated natural loess by means of shaking-table testing.Previous testing results have shown that the development process of excess void water pressure during loess liquefaction,such as accumlation,continuance,and dissipation,is the same as that with saturated sand;the essential differences between the cases of loess and sand focus only on detailed characteristics.The degree of saturation is the most important factor in controlling the liquefaction behavior of natural loess under seismic loading.For this case of the shaking-table test,the void water pressure ratio of undisturbed loess samples can reach 0.93 at saturation conditions of 90.3%.Moreover,the degree of saturation at 85%,75%,and 65% may be critical values associated with liquefaction phenoment,similar liquefaction phenomena(cyclic failure),and that without consideration of cyclic failure,respectively.In short,first-hand data of liquefaction features of natural loess acquired by the shaking-table test and corresponding analysis results based on that datacould advance the present understanding of the physical process and mechanism of saturated soil under seismic loading.
