MODELLING FRC INFRASTRUCTURES TAKING INTO ACCOUNTTHE SOIL-STRUCTURE INTERACTION

The favourable effect that fibres provide at concrete crack initiation and propagation is especially notable in structures of high redundant supports, such is the case of concrete infrastructures surrounded by soil. If the design of these concrete structures is governed by crack width restrictions, fibre reinforced concrete is even a more competitive solution, since the stress redistribution provided by fibres bridging the micro-cracks allows the formation of diffuse crack patterns of reduced crack width. If these structures are precast with high strength concrete, and composed by thin walled components, fibres can effectively replace the total conventional transversal reinforcement, as well as a significant percentage of flexural reinforcement, resulting high competitive structures in economic and functional terms. However, to assess the fibre reinforcement benefits in this type of engineering problems, the concrete post-cracking behaviour and the soil-structure interaction behaviour need to be modelled as accurately as possible. In this paper, a FEM-based model is briefly developed and applied to box culvert structures. The model is described and a preliminary application is analysed. The main results are presented and discussed.