Assessment of steel heritage bridges
Heritage truss railway bridges with rivetted connections are the focus here. Different bridges share similar topology suitable for parametric design. The example modeled a bridge over Vltava in Tábor with 2 simply supported spans, arch trusses with top deck. The longer span measures 61.5 m long and 3.6 m wide. The second steel span is 37.3 m long and 2.8 m wide.
Analysis covered several heritage bridges from the late 19th or early 20th century. These are typically simply supported with straightforward structural behavior, featuring either 2 I sections or 2 identical main girders (arch or constant height). Hand-calculated when built 100+ years ago, they now require special assessment approaches due to beam weakening from corrosion. Corrosion investigation and steel property testing are necessary for safe assessment. Modeling should consider rivetted connection stiffness, particularly for deck elements. Major connection plates may be modeled with beam elements to better represent internal force transfer.
Larger spans (over 40 m) typically share the same main arch truss configuration, longitudinal diagonals, and transverse bracing. Deck and bracing elements often follow similar patterns. With few configuration variants and basic dimensions, Table Input enables quick, accurate modeling.
Reference: Contruss Engineering, 4/2019, www.contruss.cz
