Dynamic compaction mechod is the primary method to address the collapsibility of loess

and water injection for moisture enhancement is a decisive factor in ensuring the quality of dynamic compaction.However

in practical engineering applications

water injection for moisture enhancement often faces significant challenges

such as uneven diffusion in“dual-layer structure”soil and insufficient moisture levels to meet the requirements of dynamic compaction.This paper investigates the diffusion patterns of water injection in“dual-layer structure”soils

employing two different methods of water injection for moisture enhancement.It compares the relationship between actual moisture content

deformation modulus

and settlement after compaction before and after moisture enhancement.The results show that the proposed graded and layered humidification method demonstrates a highly significant effect in addressing the moisture enhancement challenges associated with dynamic compaction in“dual-layer structure”soils.