The protection and conservation of cultural and architectural heritage are funda-mental problems worldwide and require a multidisciplinary approach. Interventions on historical structures require materials and construction techniques that can in-crease safety and preserve the values of historic buildings. Vibration-based monitoring techniques can therefore play an important role in the field of cultural heritage conservation also thanks to their low invasiveness. Verification of the effectiveness of strengthening interventions is a primary issue that can be addressed using advanced monitoring techniques. The introduction and evolution of new technologies such as BIM combined with monitoring techniques, OMA and model updating has paved the way for the devel-opment of new integrated tools for the management and maintenance of structures in an innovative way. An overview of structural monitoring and the potential offered as a tool for the sur-vey of damage in masonry structures was carried out. The damage indices present in the literature were reviewed in order to select appropriate damage sensitive features for Structural Health Monitoring. The implementation of adequate structural moni-toring strategies requires, on the other hand, an in-depth knowledge of the features of the measurement chains and advanced tools for data storage and management. A monitoring system has been developed for, and installed on the bell tower of Civi-tacampomarano. The monitoring system continuously acquires and processes the re-sponse to environmental vibrations. The dynamic behavior of the bell tower has been continuously characterized under operating conditions and through automatic OMA techniques the influence of temperature on the dynamic properties of the structure was investigated. The monitoring system also recorded the response of the bell tower following a seis-mic event of magnitude 4.6. The seismic input caused a drop in the natural frequen-cies of the structure, whose effects will be the subject of future studies. In addition, the use of BIM as a support tool for building management has been in-vestigated. The results of analyses carried out to verify the interoperability between the main BIM software through the open IFC format and between these and some fi-nite element calculation software have been reported. Then, advantages and disad-vantages of using the IFC format were discussed. The combination of advanced structural monitoring techniques and new BIM tools lead to a new approach for the development of tools that are able to assess the health status and can proactively support the maintenance and management of structures. Through the use of automatic OMA techniques, it is possible to transfer data and in-formation on the current state of the structure to a BIM model and make them avail-able for model updating analyses. By combining BIM, SHM and model updating, an innovative automated procedure was proposed for the creation of a digital twin of a historic structure, capable of managing the entire process on a single platform and the advantages were discussed. The realization of a digital twin can help to identify uncertain modeling parameters and to evaluate and manage the structural behavior under operating conditions throughout the life cycle of the structure. The advantage of having a completely automated procedure is the possibility of having the model continuously updated over time and usable for simulations and structural analyses. Structural monitoring and OMA techniques are effective for extracting the modal properties (natural frequencies, damping, mode shapes) of the structure as damage-sensitive characteristics, but also offer an assessment of the effectiveness of rein-forcement systems and retrofitting interventions thanks to the changes in the dynam-ic properties before and after the intervention. Cement pastes and mortars play a fundamental role in the reinforcement and retro-fitting of structures. By solving an inverse problem and using monitoring and OMA techniques, the evolution of the Young's modulus relating to cementitious pastes made with pozzolanic and ordinary Portland cements from the earliest stages of maturation was evaluated. A set up for early age curing was developed. The exten-sive test campaign was carried out to investigate the effects of storage at different months on the curing of ordinary pozzolanic and Portland cements; tests were also carried out to observe the effect of temperature. The obtained results provided a phe-nomenological approach to assess the influence of prehydration on the early age evo-lution of mechanical properties. Future developments will concern: - the enhancement of the measurement chain of the bell tower, the improvement of the analysis settings and the implementation of tools for the removal of en-vironmental effects; - the integration of BIM, SHM and model updating with other technologies such as GIS, virtual reality, augmented reality and metaverse providing innovative solutions for the design, management and maintenance of structures; - the extension of the experimental tests to characterize the early age response of cement matrices for FRCM.

Tecnologie innovative per il monitoraggio di strutture storiche e la gestione degli interventi

CIERI, Luigi
2023-09-26

Abstract

The protection and conservation of cultural and architectural heritage are funda-mental problems worldwide and require a multidisciplinary approach. Interventions on historical structures require materials and construction techniques that can in-crease safety and preserve the values of historic buildings. Vibration-based monitoring techniques can therefore play an important role in the field of cultural heritage conservation also thanks to their low invasiveness. Verification of the effectiveness of strengthening interventions is a primary issue that can be addressed using advanced monitoring techniques. The introduction and evolution of new technologies such as BIM combined with monitoring techniques, OMA and model updating has paved the way for the devel-opment of new integrated tools for the management and maintenance of structures in an innovative way. An overview of structural monitoring and the potential offered as a tool for the sur-vey of damage in masonry structures was carried out. The damage indices present in the literature were reviewed in order to select appropriate damage sensitive features for Structural Health Monitoring. The implementation of adequate structural moni-toring strategies requires, on the other hand, an in-depth knowledge of the features of the measurement chains and advanced tools for data storage and management. A monitoring system has been developed for, and installed on the bell tower of Civi-tacampomarano. The monitoring system continuously acquires and processes the re-sponse to environmental vibrations. The dynamic behavior of the bell tower has been continuously characterized under operating conditions and through automatic OMA techniques the influence of temperature on the dynamic properties of the structure was investigated. The monitoring system also recorded the response of the bell tower following a seis-mic event of magnitude 4.6. The seismic input caused a drop in the natural frequen-cies of the structure, whose effects will be the subject of future studies. In addition, the use of BIM as a support tool for building management has been in-vestigated. The results of analyses carried out to verify the interoperability between the main BIM software through the open IFC format and between these and some fi-nite element calculation software have been reported. Then, advantages and disad-vantages of using the IFC format were discussed. The combination of advanced structural monitoring techniques and new BIM tools lead to a new approach for the development of tools that are able to assess the health status and can proactively support the maintenance and management of structures. Through the use of automatic OMA techniques, it is possible to transfer data and in-formation on the current state of the structure to a BIM model and make them avail-able for model updating analyses. By combining BIM, SHM and model updating, an innovative automated procedure was proposed for the creation of a digital twin of a historic structure, capable of managing the entire process on a single platform and the advantages were discussed. The realization of a digital twin can help to identify uncertain modeling parameters and to evaluate and manage the structural behavior under operating conditions throughout the life cycle of the structure. The advantage of having a completely automated procedure is the possibility of having the model continuously updated over time and usable for simulations and structural analyses. Structural monitoring and OMA techniques are effective for extracting the modal properties (natural frequencies, damping, mode shapes) of the structure as damage-sensitive characteristics, but also offer an assessment of the effectiveness of rein-forcement systems and retrofitting interventions thanks to the changes in the dynam-ic properties before and after the intervention. Cement pastes and mortars play a fundamental role in the reinforcement and retro-fitting of structures. By solving an inverse problem and using monitoring and OMA techniques, the evolution of the Young's modulus relating to cementitious pastes made with pozzolanic and ordinary Portland cements from the earliest stages of maturation was evaluated. A set up for early age curing was developed. The exten-sive test campaign was carried out to investigate the effects of storage at different months on the curing of ordinary pozzolanic and Portland cements; tests were also carried out to observe the effect of temperature. The obtained results provided a phe-nomenological approach to assess the influence of prehydration on the early age evo-lution of mechanical properties. Future developments will concern: - the enhancement of the measurement chain of the bell tower, the improvement of the analysis settings and the implementation of tools for the removal of en-vironmental effects; - the integration of BIM, SHM and model updating with other technologies such as GIS, virtual reality, augmented reality and metaverse providing innovative solutions for the design, management and maintenance of structures; - the extension of the experimental tests to characterize the early age response of cement matrices for FRCM.
Innovative technologies for historical structures monitoring and management of the interventions
26-set-2023
SHM; BIM; Digital Twin; Cement; Early age
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11695/126843
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