Collapse prediction and safety of masonry archesCollapse prediction and safety of masonry arches Κεφάλαιο σε Βιβλίο Book Chapter 2022-07-212020enMasonry structures without mortar or with mortar of low quality are used in several infrastructures, like bridges and retaining walls Unilateral contact plays a crucial role in their stability. Limit analysis and nonexistence of solution are related to the creation of collapse mechanisms. Open source and freely available software can be used for the analysis of such structures, usually with an acceptable for post-disaster, emergency situations. Numerical results related to a recently collapsed masonry bridge demonstrate the usage of the proposed method.http://creativecommons.org/licenses/by/4.0/1Springer Tracts in Civil EngineeringNatural Risk Management and Engineering: NatRisk Project Stavroulakis Georgios Σταυρουλακης Γεωργιος Menemenis Ioannis Μενεμενης Ιωαννης Stavroulaki Maria Σταυρουλακη Μαρια Drosopoulos Georgios Δροσοπουλος Γεωργιος Springer Nature Limit analysis Masonry arches Collapse prediction Stability of structures Solvability of unilateral contact problems