Collapse displacements for a mechanism of spreading-induced supports in a masonry arch

Abstract

Masonry arch systems and vaulted structures constitute a structural typology widely spread in the historical building heritage. Small displacements of the supports, due to different causes, among which subsidence of foundation systems or movements of underlying structures can lead the masonry arch to a condition of collapse because of gradual change in its geometry. This paper presents a tool, based on a kinematic approach, for the computation of the magnitude of the displacements that cause the collapse of circular arches subject to dead loads, and allows the evaluation of the related thrust value. A parametric study has been carried out in order to develop a deeper understanding of the influence of the involved parameters. In addition, analytic formulations of the maximum allowed displacement and the associated thrust are proposed. Finally, a case study related to the behavior of a masonry arch on spreading-induced abutments is undertaken and discussed.

Horizontal reaction components of pointed vaults

“…The kinematic theorem of Limit State Analysis was applied by Coccia et al (2015) for circular arches. The investigations pointed out that the arch thickness significantly influenced the support displacements and the horisontal reactions belonging to the collapse state.…”

Minimum thrust and minimum thickness of hemispherical masonry domes

“…Consequently, the dome slices and, producing a mechanism, adapts itself to the settlement. As in the case of the arch [10][11][12]14] or of the cross vault [10,13,15], a state of minimum thrust takes thus place in the dome. This state is so defined by a statically admissible pressure surface i.e., all contained within the dome thickness and tangent to the dome along two parallel circles to assure the formation of circular hingings producing the settlement mechanism.…”

Structural behaviour of masonry arch with no-horizontal springing settlement

“…In particular, recent studies have focused attention on the dynamic [2][3][4][5][6] and seismic behaviour [7][8][9][10][11][12][13][14][15][16][17][18][19][20] of existing masonry arch structures. One structural problem that has been rather neglected [21][22][23][24] in recent studies involves the behaviour of arches as a result of imposed settlement to the supports. The behaviour of arches with horizontal settlement has been comprehensively studied both by applying limit analysis [22][23][24] and through experimental testing [22].…”

“…One structural problem that has been rather neglected [21][22][23][24] in recent studies involves the behaviour of arches as a result of imposed settlement to the supports. The behaviour of arches with horizontal settlement has been comprehensively studied both by applying limit analysis [22][23][24] and through experimental testing [22]. Nonetheless, the structural behaviour of masonry arches undergone a non-horizontal displacement of supports is still partially unexplored.…”

“…Referring to the main studies about horizontal displacement available in literature, Ochsendorf [22] analyzed the formation of cracks of a masonry arch in relation to the horizontal thrust and the distinctive geometrical characteristics of the structure, that are thickness t, radius R and angle of embrace β, through thrust line analysis. Coccia et al [23] reviewed the Ochsendorf's work suggesting an innovative method in studying these phenomenons based on the implementation of kinematic theorem to deformed configuration of the arch. In particular, they showed that the considered collapse configuration for the masonry arch, then the position of the cracks, depend on the displacement imposed to the supports.…”