Dynamic properties of sandy soil under medium-high strain rates are of great significance for protection engineering

pile penetration

ship anchoring

aircraft landing

and so on. This paper reviews the current research status of split Hopkinson pressure bar (SHPB) impact tests and numerical simulations on sandy soil. The key issues in the research of sandy soil impact characteristics are summarized as follows: (1) The SHPB test still faces uncertainties for granular materials

such as the lack of standardized test sample size

difficulties in controlling boundary conditions

and the immaturity of triaxial testing methods. Future triaxial SHPB tests need to address issues related to measuring radial deformation of the samples and maintaining consistent confining pressure. (2) Due to uncertainties in gas and water discharge under test conditions and the presence of inertial effects

the accurate determination of strain rate effects becomes challenging. (3) The impact characteristics of granular materials are influenced by moisture content

which is correlated with changes in pore water pressure and pore air pressure. However

measuring these related variables is difficult

making it challenging to analyze the results. It is necessary to develop a device that completely eliminates the effects of gas and water discharge to mitigate the influence of boundary conditions. (4) To study the impact characteristics of sandy soils

it is necessary to overcome computational limitations and establish numerical models that account for complex mechanisms such as water content and particle fragmentation. Existing methods such as the finite element method

discrete element method

and coupled methods are unable to uniformly simulate the continuity of wave propagation and particle fragmentation. (5) It is crucial to develop constitutive models that consider the strain rate effects and can simulate complex mechanisms such as water content and particle fragmentation. This will help refine the theoretical framework of soil mechanics at medium to high strain rates.