Reliability-based seismic assessment of masonry arch bridges

Masonry arch bridges form a noteworthy portion of road and railway networks in the world, especially in Europe and Turkey. Structural assessment of such bridges is required because of their vulnerability to seismic actions. A realistic and rigorous structural assessment is important in terms of protecting cultural heritage and using resources carefully. However, there are no standardized or widely accepted procedures. This study presents an overarching reliability-based seismic assessment methodology based on analytical modeling, laboratory testing, and probabilistic assessment. It investigates the seismic behavior of masonry arch bridges and the uncertainties in the assessment methods by using di erent existing seismic analysis techniques. The Finite Element (FE) macro-modeling approach is used in modeling the behavior of the structure. System identi cation and model updating of the bridge enabled obtaining a reliable analytical model. Next, the seismic assessment is performed using Nonlinear Static Analysis (NSA), Nonlinear Dynamic Analysis (NDA), and Incremental Dynamic Analysis (IDA). This study also examines the uncertainties in obtaining the elasticity modulus of masonry by using several experiments, numerical modeling, and empirical equations. It then combines the knowledge acquired from analysis and testing for the reliability-based seismic assessment. Because there are no performance criteria available for masonry arch bridges, performance limit states for the investigated masonry arch bridge are de ned. In the end, the probability of exceedance (or failure) for each limit state is calculated by integrating the performance criteria and the results of NDA and probabilistic seismic analyses. This reliability-based seismic assessment study of a masonry arch bridge is the rst example that considers the uncertainties in material properties and uses a detailed 3D FE model to obtain reliability indexes.