Particle breakage behavior of a foundation filling material on island-reefs in the South China Sea under impact loading

Calcareous sand (CS) is a special geomaterial that is susceptible to particle breakage. In order to clarify the effects of coarse-particle content ( CC ) and impact energy ( E b ) on CS particle breakage, multiple impact tests were conducted on CS, and fractal dimension ( α ) and relative breakage ratio ( Br ) were introduced to quantitatively assess the CS particle breakage under varying conditions. According to the results, (I) the CS particle breakage during impact testing caused an increase in α. (II) The ultimate fractal dimension for CS under impact loading ranged from 2.16 to 2.73 and was only related to its initial fractal dimension. (III) A mathematical model capable of predicting the α of CS according to its initial median particle size and E b was built, and the rationality of this model was validated. (IV) The Br of CS increased following a logarithm function with increasing CC and a hyperbolic function with increasing E b . (V) The relationship between α and Br was established for CS under impact loading. These results can provide a theoretical basis for further research on the influence of particle breakage on strength parameters of CS under impact loading.