Monitoring of masonry historical constructions: 10 years of static monitoring of the world's largest oval dome

et al. 2018

Summary The need to obtain the mechanical characteristics for analysis and understanding of the mechanical behaviour of historic buildings is highlighted. Destructive tests and non‐destructive tests are widely used for this purpose; however, they only provide a value associated with a specific instant. Structural health monitoring contributes to the monitoring of specific processes before, during, or after an intervention. Nevertheless, among the available sensors, there is a lack of devices for continuous monitoring of stress variations undergone by masonry structures. In response to this need, a new stress‐measurement device for structural monitoring of masonry structures has been developed. It has the aim of determining the initial stress in masonry structural element and providing continuous control of the evolution of the stress variation. The article describes the design of the device, as well as its implementation in a historic building. Moreover, an assessment is performed of the stress variations registered in comparison with the displacements recorded in the monitored areas, as well as the influence of the thermic fluctuations on these. A good relation was confirmed between these measurements. The results demonstrate that the designed device proved to be a useful tool for monitoring structural strengthening interventions.

Section: Background and Motivationmentioning

confidence: 99%

A new device for stress monitoring of ancient masonry buildings: Pilot study and results

et al. 2018

“…These have been fundamentally applied in civil infrastructures; however, in the case of the building sector, and particularly in historic buildings, their use is quite scarce. In this context, the use of load cells can be cited as a technique for monitoring during structural interventions. Nevertheless, other than these studies, there is little work related to the monitoring of the evolution over time of stress levels in masonry structures.…”

Section: Introductionmentioning

confidence: 99%

Device for continuous assessment of uniaxial stress of existing masonry structures: Laboratory validation

et al. 2019

Summary Knowledge of the mechanical characteristics of the materials and the behaviour of the structure play an important role in the process of intervention in ancient buildings. Moreover, the heterogeneity of these structures and/or the necessity to know how effective a reinforcement will be, among other aspects, make it necessary to propose new devices and/or techniques that enable the characterisation and evaluation of the associated masonry structures. This paper presents a slightly destructive technique for continuous monitoring of stress variations undergone by existing masonry structures. It is based on the estimation of the existing stress state, and its continuous monitoring over time. The development methodology and the validation of results obtained by the stress device in laboratory are discussed. To do so, among other factors, the effect of temperature variations on the sensor records are analysed, and the relationship between the stress variations and the displacements recorded in the monitored area are evaluated. After 10 months of continuous monitoring, it could be concluded that there was a good relationship between the stress variations applied in the masonry wall and the stresses measured by the device. Besides, a notable influence of the thermal variations on the sensor registers was found. A thermal correlation coefficient was proposed, which minimised the thermal incidence on the stresses registered. Moreover, a suitable relationship was also confirmed between the manual and continuous deformation measurements. The results show the capability of the proposed device to evaluate the continuous stress monitoring of existing masonry structures during intervention processes.

“…[16,17] In fact, a SHM system can assist in evaluating the structural behaviour during all the phases of the interventions, and it allows the design solutions to be modified during the strengthening procedure. [18,19] Consequently, these methodologies are potential tools for the identification, localization, and quantification of damage in constructions, as well as proving useful in the intervention follow-up process.…”

Section: Introductionmentioning

confidence: 99%

“…It has received considerable attention and has successfully replaced traditional visual inspection for damage detection and maintenance of structures subjected to various loadings . In fact, a SHM system can assist in evaluating the structural behaviour during all the phases of the interventions, and it allows the design solutions to be modified during the strengthening procedure . Consequently, these methodologies are potential tools for the identification, localization, and quantification of damage in constructions, as well as proving useful in the intervention follow‐up process.…”

Section: Introductionmentioning

confidence: 99%

“…The selection of the SHM technique to be adopted for each specific application depends on several variables including costs, aims and scope, possible risks, importance of the building, and the available information . Normally, traditional sensors for recording the variations of parameters such as crack openings, deformations, or thermal variations are employed in the field of SHM, but new measuring approaches are also being included (e.g., strain sensors, accelerometers, fibre optic sensors, and terrestrial laser scanning). Nevertheless, these devices must be adaptable to the specific circumstances arising in each study of a historic building, with the aim of exhaustively monitoring the behaviour of its structural elements.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

An integrated structural health monitoring system for determining local/global responses of historic masonry buildings

et al. 2018

Summary In this study, an integrated structural health monitoring system was developed and applied to a masonry heritage building under rehabilitation, where diverse structural changes were made. The late 19th century building had over the years undergone significant deterioration, which brought about the appearance of serious pathological processes affecting the building's stability. In 2012, concerns over the severe cracking phenomena affecting the structure prompted the decision to monitor the structure and to undertake strengthening interventions. A global structural monitoring system was applied to the church to identify the occurrence of possible damage mechanisms and monitoring the intervention processes. The monitoring system was based on the integration of subsystems, which were implemented as and when necessary. Traditional sensors consisting of crackmeters, servo‐inclinometers, cable extension sensors, displacement transducers, wind vanes, and temperature sensors (thermo‐hygrometer and thermocouples) were installed on the building. Moreover, novel measuring approaches using stress sensors and pressure cells were used. Furthermore, manual monitoring elements were installed, which provided measurements for contrasting with those of the continuous sensors, as well as a greater number of monitoring points. Thus, the structural response was measured using 67 monitoring elements. The long‐term (5 years) monitoring results indicated that the interventions were carried out without the occurrence of any irregularity. A good relation was confirmed between the manual and continuous measurements. Moreover, the results have shown the capability of the proposed integrated system to evaluate the structural behaviour during all the phases of the interventions.