Undrained Cyclic Response and Resistance of Saturated Calcareous Sand considering Initial Static Shear Effect

Abstract

Sand elements in the natural or manmade field have often undergone initial static shear stresses before suffering cyclic loading. To explore the effect of static shear stress, a series of undrained cyclic triaxial tests were performed on dense and loose calcareous sand under different initial and cyclic shear stresses. The triaxial test results are used to describe the effect of static shear stress on the cyclic response of the calcareous sand with different relative density. Cyclic mobility, flow deformation, and residual deformation accumulation are the three main failure modes under varying static and cyclic shear stress levels. The cyclic resistance of dense sand is greater than that of loose sand, but the initial static stress has different effects on the cyclic resistance of the two kinds of sand. The dense sand owns a higher cyclic resistance with SSR increasing, while for the loose sand, 0.12 is the critical SSR corresponding to the lowest value of the cyclic resistance. The dense sand has more fast accumulation of dissipated energy, compared with loose sand. Additionally, an exponential relationship is established between static shear stress, relative density, and normalized energy density.

Experimental Study of Awash Soil under Static and Cyclic Shear Loading

“…Li et al [16] studied the efect of static shear stress on the cyclic response of calcareous sand with diferent relative densities under cyclic loading. Tey showed that the cyclic resistance of dense sand is greater than that of loose sand, and it accumulated dissipated energy faster than loose sand.…”

Simulation Analysis of Temperature Effects on the Shear Behavior of Gassy Sand

“…As a kind of special unsaturated soil, gassy soil is widely distributed in coastal areas and alluvial plains. During the construction of subway, foundation pit, large sea crossing bridge, deep-water port wharf, and slope engineering in these areas [1][2][3], some engineering accidents have been caused due to the lack of understanding of the engineering mechanical properties of gassy soil [4][5][6][7][8]. Different from the general unsaturated soil, the gas in the gassy soil is in a closed state, that is, there are gas bubbles in the soil.…”