PHYSICAL INDEXES OF CARBONATE SAND WITH DYNAMIC PENETRATION TEST

Carbonate sand usually refers to the sediment with calcium carbonate content more than 50%. It has special physical and mechanical properties compared with the terrestrial sand. The dynamic cone penetration test is widely used to evaluate the engineering properties of soils. At present, the study of relationship between dynamic cone penetration indexes and soil physical properties are focused on clay and siliceous sand while weather the existing evaluation method is suitable for carbonate sand is controversial. To address the problem, in this study, a serious of field light dynamic penetration test are conducted to investigate the relationships of the dynamic cone penetration index with respect to the physical indexes including mean particle size, various densities, and relative density of the carbonate sand. Based on results of in situ tests, the relationships between the dynamic cone penetration index and physical indexes are established for the carbonate sand. The residual analysis shows that these formulas achieve certain accuracy. It can be found that to establish the relationship between penetration index and various densities as well as relative density need to consider the influence of average particle size, which is related to the easy crushing of carbonate sand. These results can be useful for engineers to evaluate engineering properties of carbonate sand in practice.