Augustus Bridge in Narni (Italy): Seismic Vulnerability Assessment of the Still Standing Part, Possible Causes of Collapse, and Importance of the Roman Concrete Infill in the Seismic-Resistant Behavior

Abstract

The final results of advanced FE analyses performed on a Roman arch bridge, namely the Augustus Bridge (Ponte di Augusto) in Narni, center Italy are presented. The bridge, one of the most impressive Roman artworks, has been injured by several traumatic events during the millennia, the result of which is its present ruined condition. The aims are manifold, starting from a better understanding of the causes at the base of the partial collapse occurred on the central pier, passing through a seismic assessment of the ruined still standing part and ending with a discussion on the role played by Roman concrete on the stability against horizontal actions. An advanced material model exhibiting damage, plastic deformation, and softening in both tension and compression is adopted for Roman concrete. Both the case of a foundation settlement of the central pier and the application of a seismic excitation are investigated, by means of nonlinear static and nonlinear dynamic analyses. Numerical simulations are carried out within the FE code ABAQUS by means of detailed 3D models, using historical documentation and previous results of the latest research carried out on materials, assuming realistic models on both the uniaxial stress-strain relationships under nonlinear load-unload conditions by using independent damage parameters in tension and compression, and the multiaxial behavior ruled by a regularized Drucker-Prager strength criterion. The methodological approach turns out to be potentially valid for all existing Roman bridges. Results highlight the vulnerability of the ruins, that the collapse of the central part was probably due to settlement of the central pier and that Roman concrete plays a crucial role in increasing the stability against earthquake actions

Ayvalıkemer (Sillyon) historical masonry arch bridge: a multidisciplinary approach for structural assessment using point cloud data obtained by terrestrial laser scanning (TLS)

“…The Concrete Damage Plasticity (CDP) material model, which has been widely used in recent years for the stress-strain behavior of brittle materials, is also used in this study to express the nonlinear part of the behavior [69][70][71]. Compressive stress-strain behavior of the material and uniaxial tensile stress-strain behavior is defined by the relations [72,73] shown in Eqs.…”

“…f b0 /f c0 is the ratio of the biaxial compressive strength of the material to the uniaxial compressive strength. The CDP parameters considered for the whole structure are assumed as; β, 36; e, 0.1; f b0 /f c0 , 1.16 and K, 0.667 respectively [71].…”

Seismic vulnerability assessment and fragility curves for a multistorey gallery arch bridge

“…Further, it represents the response of the whole structure during the analysis. The control node has been kept at the top of the bridge structure in past studies [43,45,46]. In this study, the control node is selected at the top of the middle arch (see Fig.…”

Serviceability analysis and increased axle load performance of heritage arch gallery railway bridge

“…The whole FE model of the bridge is presented in Figure 6. Due to the absence of any material testing on the structure, the initial value of Young's modulus adopted for the stone masonry was 10,000 MPa, density 2400 kg/m3 and Poisson's ratio was kept 0.2 which is adopted from the literature (Bertolesi, Milani, Lopane, & Acito, 2017;Fanning & Boothby, 2001;Milani & Lourenço, 2012). The bridge is located in a hilly region and it is assumed that the bridge is constructed on very hard and stiff strata.…”