In this paper, an innovative strategy for numerical modeling of multi-arch masonry bridges subjected to reinforcement interventions is proposed. In particular, new reinforcement systems called FRCM (Fiber Reinforced Concrete Matrix) consisting of cementitious matrices reinforced by fiber networks will be studied; this type of system has high strength and durability and greater compatibility with the masonry support than traditional polymer matrix reinforcement systems. The aim of the study conducted is to develop realistic modeling that can simulate the actual crisis mechanisms occurring on the reinforced structure. This study proposes the FEM modeling of multi-arch masonry bridges on which a particular type of FRCM composed of PBO nets is placed. In order to take into account the nonlinear behaviour of the material, to the parts of the structure composed of masonry were assigned Concrete Smeared Crack model as the constitutive behaviour [1]; the constitutive laws were defined using previous studies results [2, 3]. The PBO network was modeled using Embedded Truss finite elements implemented in the software used for modeling (Midas FEA NX). The aim is to develop models that account for the reinforcement system in detail but, at the same time are streamlined and ensure reduced computation time. For these reasons, the FRCM system was realized by means of an equivalent mesh network instead of the real one with very fine mesh, so as to greatly reduce the computational burden of the whole models. Preliminary tests were carried out to verify the reliability and effectiveness of the developed strategy; finally, the same methodology was applied on full-scale multi-arch railway bridges models. Modal and Pushover analyses [4] were performed on the developed models, after which the results were compared with reference to the models with and without the application of the reinforcement system.