Seismic capacity of masonry arches with irregular abutments and arch thickness Paolo Zampieri ⇑ , Nicolò Simoncello, Carlo Pellegrino Dept. of Civil, Environmental and Architectural Engineering, University of Padova, Italy highlights  Existing masonry arch bridges need to be assessed in order to know their seismic capacity;  Irregularities in abutment height increase the seismic vulnerability of the arch;  Increasing arch thickness near the impost should have a positive effect;  Limit analysis appears to be reliable for the seismic assessment of masonry arches. article info Article history: Received 20 August 2018 Received in revised form 8 November 2018 Accepted 12 December 2018 Keywords: Arch Masonry Limit analysis Irregular geometry FE analysis abstract The simplest structural analysis for assessing the seismic capacity of a masonry arch is limit analysis. In fact, assuming an equivalent static seismic load, this method can be used to determine the lateral accel- eration leading to the collapse mechanism. In this work, applying an analytical procedure, extensive para- metric analysis was carried out to describe the seismic capacity of masonry arch structures with irregular geometry. In particular, arches with different abutment heights and discontinuous thicknesses have been examined. The results have been compared against those obtained by finite element analysis and by small scale experimental tests, and a good correlation has been found. Ó 2019 Elsevier Ltd. All rights reserved. 1. Introduction The seismic assessment of masonry arch structures is important for both preserving and maintaining the cultural and architectural heritage of historic masonry buildings. The simplest and most ele- mentary method used for the seismic assessment of masonry arches is limit analysis, which despite being a simple structural cal- culation method, provides results that accurately describe the seis- mic behaviour of the masonry arch structure. This method of analysis originates from oldest structural analysis theories [1,2] and is still used in modern studies with the utilization of the com- putational methods [3–5]. The first work in providing an overall idea of the seismic beha- viour of a masonry arch was developed by Clemente in 1998 [6]. In addition to dynamic analysis, Clemente used limit analysis to cal- culate the value of seismic acceleration and to determine the positions of the four collapse hinges for arches with different semi-circular geometries. Other authors have since used the same approach and extended Clemente’s work to non-circular arches [7–9]. Other researches have focused on the seismic capacity and collapse mechanisms of arches with slender abutments using the limit analysis method [10–13]. Limit analysis has also been used, in recent studies, to assess the seismic capacity of masonry bridges, to describe the local collapse mechanisms [14,15] (overturning of the spandrel wall) and to describe the global mechanisms: longitu- dinal mechanism [15] (in-plane of arch) and transverse mechanism [14] (out-of-plane of arch) of masonry bridges. Finally, another very important aspect relating to the seismic behaviour of masonry arch structures recently studied by some authors [16–18] is the influence of the geometric uncertainty of arches in the collapse multiplier of the seismic loads. In addition to limit analysis, more recent seismic analyses [19– 24] have been carried out in some studies, such as non-linear static and dynamic analysis. In particular, non-linear dynamic analysis is able to accurately describe the dynamic behaviour of the structure that develops during earthquakes. https://doi.org/10.1016/j.conbuildmat.2018.12.063 0950-0618/Ó 2019 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: paolo.zampieri@dicea.unipd.it (P. Zampieri). Construction and Building Materials 201 (2019) 786–806 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat