Study On Mechanical Properties Of Sand-filled Reefs In The South China Sea

Reef sand is a kind of sediment that is widely distributed in the South China Sea and is composed of the remains of calcium organisms and its debris.It has engineering characteristics such as fragility,difficulty in saturation,and high void ratio.In this paper,through a series of indoor tests,the effects of gradation,dry density and fine-grained soil on the permeability,compressibility and shear strength of reef sand have been studied.Get the following results:When the coefficient of non-uniformity is constant,the shear strength increases first and then decreases with the increase of the curvature coefficient of the reef sand.The compression coefficient gradually increases and the permeability coefficient increases.When the curvature coefficient is constant,the shear strength becomes uneven.As the coefficient increases,the shear strength gradually increases,the compression coefficient decreases,and the permeability coefficient increases.As the content of fine-grained soil increases,the internal friction angle increases first and then decreases,and both the compressibility and the permeability coefficient decrease.Under different relative densities,the dynamic strength increases with the increase of fine-grained soil content under the specified number of vibrations.Through the test of the bearing capacity of the slope foundation,it is found that the bearing capacity of the slope foundation increases first and then decreases with the increase of the fine-grained soil content.When the non-uniform coefficient is constant,the curvature coefficient increases,and the bearing capacity of the slope foundation is similar.It first increases and then decreases.Through the above studies,the physical and mechanical properties of the reef sand were discussed in depth,and the variation regularity of the strength and deformation index of the reef sand was studied.The research results provided a theoretical and technical reference for the scientific research and engineering application of the reef sand foundation.