p-y curves

[billu]

hello everyone,
For modelling a pipeline, during step of creating spring materials, do we have to define p-y criteria like we do in during modelling of pile foundation, or do we have to define spring materials(force-deformation relationship) like this
uniaxialMaterial ElasticPP 1 472959.528571 0.003000 -0.003000 0.0; # Force - Deformation Relationship For Axial Soil Springs
uniaxialMaterial ElasticPP 2 984545.454545 0.003000 0.0 0.0; # Force - Deformation Relationship For Uplift Vertical Soil Springs
uniaxialMaterial ElasticPP 3 7244248.439845 0.0 -0.003000 0.0; # Force - Deformation Relationship For Vertical Downward Soil Springs
uniaxialMaterial ElasticPP 4 1132458.093238 0.008929 -0.008929 0.0; # Force - Deformation Relationship For Transverse Soil Springs
uniaxialMaterial Parallel 5 2 3; # Force - Deformation Relationship For Vertical Soil Springs

I am getting confused in this step, Please i need ur guideline guys.Thanks in Advance.