Graded macadam fillings

the core filling of heavy haul railway subgrade bed is most affected by the train loading. Therefore

it is particularly important to study the dynamic behavior and accumulative plastic strain evolution characteristics of graded macadam filling under cyclic loadings. Firstly

graded macadam fillings with different fine particle contents were prepared

and a series of large-scale dynamic triaxial tests was conducted to explore the coupling influence mechanism of fine particle content

confining pressure

and dynamic stress amplitude on the specimen accumulative plastic strain under cyclic loadings. Additionally

based on the plastic stability theory

the dynamic behavior of specimens under different stress levels was determined

and the calculation model of critical dynamic stress in the plastic creep state was obtained considering the parameters of confining pressure and fine particle content. Finally

in combination with the experimental data

an accumulative plastic strain prediction model was established considering the stress level and fine particle content parameters for the dynamic behavior of plastic creep

and the physical meaning of each parameter was clarified. The research results can provide a reference for the health status assessment of existing heavy haul railway subgrades and the subgrade structure design considering the comprehensive control of strength and deformation.