Arch bridges subject to pier settlements: continuous vs. piecewise rigid displacement methods

Abstract Settlements severely affect historic masonry arch bridges worldwide. There are countless examples of structural dislocations and ruins in recent years due to severe settlements at the base pier foundations, often caused by shipworm infestation wooden foundations or scouring riverbed erosion phenomena. The present paper proposes an original way approach failure analysis settled bridges. proposed method combines two different 2D numerical models for prediction bridge capacity against safety assessment. first one is Piecewise Rigid Displacement method, i.e. a block-based limit using well known Heyman's hypotheses; second continuous Finite Element approach. case study four-span Deba Bridge (Spain, 2018) presented with aim illustrate how methods work. produced satisfactory results applying both separately, confirmation their reliability. Their combination also allowed obtain significantly reduction computational cost improvement accuracy. A sensitivity path-following were performed demonstrate robustness method. obtained simulations highlighted that do not depend on friction angle proper evolution behavior can be only taking into account geometric nonlinearities. Such once again arches geometry prevails over mechanical parameters. current paves fruitful use approaches wider range applications, as, example, mechanism identification displacement assessment structures under overloading as seismic loads.