Ballast settlement analysis considering spatial variation of elastoplastic behavior of ballast material

Abstract

In the ballast settlement analysis with the cyclic densification model, the influence of spatial variation of the elastoplastic behavior on the simulation results is investigated through numerical tests. The spatial variation of elastoplastic behavior of railway ballast is considered as the spatial variation of the material parameters of the present elastoplastic model. The large variation of the simulated ballast settlement results from the spatial variation of the material parameters on elastic behavior K_ref , p_ref and n^e and the parameters on the initial strength of flictional sliding H₀ and h₀. The spatial variation on h₀ increases the uncertainty of the simulated results in progression of the number of loading cycles. This is because the finite element solution illustrates the localized deformation on frictional sliding of the ballast material.