A Methodological Approach to Evaluate Seismic Vulnerability of Masonry Cathedrals

The seismic analysis of historical and monumental masonry buildings, especially churches and cathedrals, is challenging and expensive. These difficulties are mainly related to complex geometry and the mechanical modelling of historic masonry structures. This paper aims to show the methodological approach to evaluate the seismic vulnerability of Masonry Cathedrals by modelling seismic analysis. The numerical finite element model, modelled with solid elements, was optimised based on identifying the primary dynamic properties performed in ambient and seismic excitations recorded by a continuous dynamic monitoring system in operation since 2015. We carried out linear dynamic analyses for the optimised model of the entire structure. We also carried out non-linear dynamic analyses for the vaults, where damage concentrations were detected after various seismic events. The linear dynamic analysis of the optimised entire structural model aimed to estimate the time histories of acceleration at the connection areas between the vaults to the vertical structures. The numerical analysis results were consistent with the damage maps identified for the actual structure. Furthermore, the numerical model and the analysis procedure showed an excellent ability to reproduce the accurate structural response

Dynamic response of PC bridge beams under different damages

The present paper describes the dynamic test campaign on prestressed concrete bridge beams taken from a dismantled viaduct in Turin, Italy after a service life of 50 years in the framework of BRIDGE|50 research project. Dynamic measurements were previously performed on the decks from which the 29 beams were taken to characterize the behaviour of the viaduct in service condition. Successively the single beams are tested to analyse and evaluate the effects of the different damage levels on the dynamic properties. The vibration data have been collected before the application of static load, after the first cracking condition and after the maximum load applied on the beam to extract the principal modal components. The results highlight the correlation among the evolution of the damage and the dynamic response of the beam and then the effectiveness of vibration tests to identify the occurrence of damages and follow their evolution. The experimental findings could be used in future works to explore the effects of damages of the single beams on the global response of this bridge typology. This work presents the results of the experimental tests on the first eight beams tested

Experimental evidence and prediction of soil-structure interaction effects for a masonry tower

Remedial actions on historical buildings have to be planned carefully in order to preserve not only the shape and appearance of the monument but also its historical and material integrity. This requires a deep knowledge of the behaviour of the structure, based on long term observations, and quite often the interaction with soil plays a relevant role. In particular, this interaction cannot be neglected when dealing when assessing both seismic vulnerability and long-term behaviour. Although advanced numerical tools are increasingly available, simple approaches still play a fundamental role for the understanding of the actual behaviour of complex structural systems in the engineering practice. In this work a rational framework for soil-structure interaction analysis is proposed and validated by using experimental data from a permanent monitoring system installed on a masonry tower in Italy

Large-scale experimental testing of 50-year-old prestressed concrete bridge girder

This paper reports on large-scale loading tests survey carried out on 50-year-oldprestressed concrete girders as part of the BRIDGE|50 research project (www.bridge50.org).The girders were retrieved from an existing viaduct in Turin, Italy. The prestressed concreteelements were 19.2 m long and had an I-shaped cross-section with a cast-in-situ slab. Variabledamages were found, due to in-service deterioration and/or subsequent lifting operations duringthe demolition phase. Each specimen was subjected to static tests using monotonic or cyclicloading up to the ultimate load. This paper reports the results of tests on the second group offour girders, comparing their load-deflection responses and strains with those of the first groupsubjected to a different static scheme. The experimental findings highlight the global structuralresponse from bending to bending/shear failure; the outcomes will define a valuable referencedatabase for assessing the residual structural performance of existing girder bridges

Rilievo 3D e monitoraggio dinamico della Torre degli Smeducci e del campanile del Duomo vecchio a San Severino Marche

Le attività della task force del Politecnico nell’Italia Centrale, nelle fasi post sisma del 2016, sono state indirizzate non solo alle aree epicentrali, ma si sono estese anche ad aree del cratere sismico che hanno subito danneggiamenti meno importanti. In queste aree le attività sono state rivolte alla analisi di beni monumentali ad alta vulnerabilità che hanno subito danneggiamenti limitati. In questo contesto si inquadrano le indagini condotte su due torri storiche di San Severino Marche, la Torre del Duomo Vecchio e la Torre degli Smeducci. Tali attività fanno parte di un piano di cooperazione strategica tra il Comune di San Severino Marche, il Politecnico di Torino e di Nagoya City University (Giappone)

Prova di permeabilità in sito

Atti del Dipartimento di Ingegneria Strutturale - Politecnico di Torino - N. 2