Two criteria for effective improvement depth of sand foundation under dynamic compaction using discrete element method

Bad engineering geological conditions restrict the use of construction sites. Dynamic compaction method is efficient in improving the strength of soils, reducing the porosity of soils and improving the mechanical characteristics of sands, so it has been widely used in ground treatment. At present, most of the studies on dynamic compaction are based on the idea of continuous mechanics and lack the analysis of the microscopic mechanism that causes the macroscopic phenomenon of soils, so discrete element method was employed to simulate the centrifuge test of dry sand under dynamic compaction, and the effective improvement depth of foundation was studied in this paper from a microscopic view. Relative density increment of 25% and vertical strain of 5% were proposed to determine the effective improvement depth of sand foundation under dynamic compaction. The two criteria proposed in this paper were effective and the results were compared with those of the Technical code for building foundation treatment. Finally, the influence of porosity on effective improvement depth was further analyzed.