Interoperability between structural and geotechnical analysis for the study of safety in existing bridges

Abstract

In recent years, the engineering community has shown a significant increase in interest in the field of soil-structure interaction. This problem is undoubtedly one of the most complex. Despite the exponential increase in computer performance in the last two decades, followed by the continuous development of numerical methods, the interaction between structural analysis programs and geotechnical issues remains limited. Specialized calculation codes for structural engineering and geotechnical engineering often operate independently. The reason for this separation lies in the highly specialized capabilities that a solver designed for geotechnical issues must possess. However, it remains crucial to incorporate the structural element within its geotechnical context, especially in the case of structures that are fully or partially embedded in the ground, such as tunnels, retaining walls, bridge abutments, and so on. There exists a mutual and reciprocal influence of the stress-strain state: the stiffness (and strength) of the foundation determines the response of the structure, which in turn affects the response of the foundation through its own stiffness. In many projects, there is an increasing demand to develop analyses that harness the full potential of both the structural and geotechnical aspects. Hence, there is a clear need to establish a connection between these two computational environments. The proposed solution involves the interaction of two programs: Midas Civil, an essential tool for structural engineers, and Flac 3D, a general-purpose software for geotechnical engineering. As explained further, this interaction is made possible thanks to the flexibility and openness of both software codes. Referring to a real case study of a road bridge with a superstructure consisting of reinforced concrete beams, this paper will illustrate the main challenges, significant steps, and undeniable advantages obtained through this approach.