The roof supporting systems of most Romanic Churches consist of a series of multiple-leaf masonry arches sustained by buttresses which have usually experienced time-dependent rotation with appreciable outward displacements on the top. Due to the absence of ties and to the intrinsic fragility of the materials, geometric modifications of the mechanical system are so important that, in many cases, curvature inversions near the arch key are produced. This problem is examined, looking in particular at the evaluation of the structural safety of these systems. With reference to a specific case, completely non-linear simulations were performed to investigate quantitative aspects of the degradation. Constitutive models for the layer interfaces were adopted: perfect bonding and radial tension response, Coulomb friction and no-tension law in radial direction, and no-friction and no-tension law in radial direction. In all cases, the non-linear constitutive relations which characterise single layers are complied with. Numerical results show the lowering of the collapse multiplier with evolution of the geometry, emphasised by using poorer and poorer response models for the layer interface response. Some restoration procedures to assess an adequate safe margin for a damaged arch are also outlined. Abstract only. Azprod Masonry: Loadbearing masonry,
Primary author(s): Capsoni A, Fontana A
Source: 12th IB2MaC. Twelfth Int.Brick/Block Masonry Conf. Proc.
Madrid,25-28 June 2000,p.595