Experimental and numerical investigation on the dynamic behavior of slopes in calcareous sand during earthquakes.

To date, the dynamic behavior of slopes in calcareous sand is unclear owing to the marine biological origin of calcareous sand. In this study, the internal deformation and the liquefaction mechanism of calcareous sand slopes were investigated by shaking table tests and numerical simulations. The influence of the presence of initial shear stress due to site inclination on the dynamic response of the slope was considered. Moreover, based on the microscopic particle properties of calcareous sand, the special dynamic response of the calcareous-sand slope during earthquakes was explored through the parallel test with the quartz sand field. The results reveal that calcareous-sand slopes exhibit higher dynamic stability during earthquakes than quartz-sand slopes, which is related to the larger occlusion caused by the irregular shapes and porosities of calcareous sand particles. However, the calcareous-sand slope still demonstrates a horizontal displacement of 0.32 times the slope height under strong earthquakes. Moreover, the settlement of the calcareous-sand slope suddenly increased 60 cm from the slope top, while that of the quartz-sand slope decreased with an increase in the distance from the slope top. The seismic protection strategies involving the use of quartz-sand slopes in the calcareous-sand slopes are inapplicable. [ABSTRACT FROM AUTHOR]