Abstract: The dynamic cone penetration test (DCPT) has been widely used in predicting the relative compaction of the foundation soils. However, the current formulas might not be suitable for the calcareous sand soils. To address the problem, a series of in situ and model DCPT were conducted to obtain the relationship between the light dynamic penetration index and relative compaction for the calcareous sand soils. The results show that the effect of particle size on the penetration of calcareous sand is more significant than that of the quartz sand soils. Under the similar relative compaction, the penetration of calcareous sand soils is smaller than that of the quartz sand soils with similar gradation. For engineering applications, a method which could transform the penetration index between the different kinds of DCPT is proposed according to the improved Butterfield's dimensional analysis theory. Then the light dynamic penetration index is transformed to the heavy dynamic penetration index using this method, so that a relationship between the heavy dynamic penetration index and relative compaction of the calcareous sand soils is obtained. Finally, the relationship was verified based on the results of the field heavy dynamic penetration test.

Key words: dynamic cone penetration test, calcareous sand soil, penetration index, relative compaction, dimensional analysis