Specify internal friction angle 30-40 deg; dilation angle slightly higher than 0 (as Abaqus does not allow for zero value), yield stress 10-35KPa (depending upon gravel and compaction) + no hardening or very low hardening, as ballast prism should work almost without degradation of hysteresis loops.

sir, I am working on cylindrical ballast model in abaqus, friction angle 45 degree,dilation angle 15 degree. I need drucker  prager hardening yield stress and absolute plastic strain data for static load analysis then i can get stress-strain plot at different loading. Can you suggest me ?

I use parameters indicated in my previous post for modelling dynamic behaviour of railroads (see one of the movies in my publications). People from the experimental department recommend them for dynamic simulations.

Whatever experimental data I get from literature that is for fixed load and confining pressure but if i want to check it for different  load ,young's modulus and  confining pressure then yield stress and plastic strain should be different. So, If i will get basic yield stress-plastic strain for ballast then i can analyse  it at any load and any confining. If you know then,please help me

Actually, confining pressure at the bottom of a typical ballast prism of ~0.6 m height is about 10-15 KPa, and at the upper part confining pressue vanishes, at these condions deviatoric loading part becomes most important for study plastic effects.

That is okay ,but how can i get yield stress and absolute plastic strain data for railway ballast? If you can refer some journals then plz.

See Phd thesis by Dr Loh "Behaviour of railway track subgrade under cyclic loading"