Methods for estimating the post-cyclic settlement of Hormuz Island calcareous sand: an experimental study

Abstract

The surficial settlement due to the dissipation of excess pore water pressure after a cyclic loading, such as an earthquake, is important in structures located on soil materials. Many efforts have been made to calculate the post-cyclic settlement of siliceous soils. This study focused on different methods for estimating the post-cyclic volumetric strain of Hormuz Island soil as a marine calcareous soil. Calcareous soils cover about 40% of the ocean surface and are located in tropical and subtropical regions. The calcareous specimens were prepared in different relative densities and consolidated under an effective confining pressure of 150 kPa. Cyclic loading under stress-controlled and undrained conditions was applied to the samples using a hollow cylindrical torsional shear apparatus. The tests were terminated at different excess pore water pressure ratios and were then drained. The results showed that the physical properties of soil grains play a key role in mechanical behavior of this deposit. Estimation methods for calculating the post-cyclic volumetric settlement of Hormuz Island sand were introduced using the excess pore water pressure ratio, the maximum cyclic shear strain amplitude, the dissipated energy, the standard penetration number, the cone penetration resistance, the shear wave velocity and the liquefaction safety factor.