On the Combined Use of Ground Penetrating Radar and Crack Meter Sensors for Structural Monitoring: Application to the Historical Consoli Palace in Gubbio, Italy

The paper deals with joint use of non-invasive monitoring technologies and civil engineering analysis methods aimed at providing multi-sensing information about the structural health of historical and cultural assets. Specifically, linear variable displacement transducers (LVDT) and ground penetrating radar (GPR) are considered for monitoring a significant crack affecting the Consoli Palace in Gubbio, Italy, precisely one of the walls of the cross-hall leading to the Loggia. In this frame, LVDT is adopted to control horizontal amplitude variations of the crack, while GPR is applied to investigate the wall interior and to detect the occurrence of inner issues related to the visible appearance of the crack on the wall surface. The effectiveness of GPR surveys is improved by means of a microwave tomography-based data processing strategy. The main result is that there is a consistency between the monitoring outputs of LVDT, which allowed us to display the crack widening/contraction due to the seasonal temperature variations, and the fact that no significant changes of the geometry of the inner areas of the walls were observed by the GPR

Ground Penetrating Radar applied to monumental stone conservation: application to the Rock Necropolis of San Vítor de Barxacova in NW Spain

This paper deals with the application of the Ground Penetrating Radar (GPR) method in the assessment of stone monuments. Compilation of published works and a discussion of their main findings are first addressed. Next, to show the potential of the method, a case study is presented aiming to assess the state of conservation of the rock necropolis of San Vítor de Barxacova (Ourense, Spain) consisting of 56 anthropomorphic graves carved into the natural rock. Fieldwork was carried out using a GPR system equipped with a 2.3 GHz central frequency antenna. The main goal of this study is to provide an effective approach for the detection and localization of internal damages such as fractures and voids. New amplitude-based 2D and 3D imaging strategies are presented aiming to improve damage detection. A new approach was also developed to digitize the extracted information into a point cloud format, thus improving the possibilities for 3D visualization with the surrounding environment. Although a total of 39 graves were surveyed, only 13 graves are included in this paper due to their singularity and relevant results. The potential of using GPR tests for the assessment of the conservation state of monumental stone structures is also discussed.Xunta de Galicia | Ref. ED431F 2021/08Ministerio de Ciencia e Innovación | Ref. RYC2019-026604-IAgencia Estatal de Investigación | Ref. RTI2018-095893-B-C2

Imaging Cultural Heritage at Different Scales: Part I, the Micro-Scale (Manufacts)

Applications of non-invasive sensing techniques to investigate the internal structure and surface of precious and delicate objects represent a very important and consolidated research field in the scientific domain of cultural heritage knowledge and conservation. The present article is the first of three reviews focused on contact and non-contact imaging techniques applied to surveying cultural heritage at micro- (i.e., manufacts), meso- (sites) and macro-scales (landscapes). The capability to infer variations in geometrical and physical properties across the inspected surfaces or volumes is the unifying factor of these techniques, allowing scientists to discover new historical sites or to image their spatial extent and material features at different scales, from landscape to artifact. This first part concentrates on the micro-scale, i.e., inspection, study and characterization of small objects (ancient papers, paintings, statues, archaeological findings, architectural elements, etc.) from surface to internal properties

Imaging cultural heritage at different scales : part I, the micro-scale (manufacts)

Applications of non-invasive sensing techniques to investigate the internal structure and surface of precious and delicate objects represent a very important and consolidated research field in the scientific domain of cultural heritage knowledge and conservation. The present article is the first of three reviews focused on contact and non-contact imaging techniques applied to surveying cultural heritage at micro- (i.e., manufacts), meso- (sites) and macro-scales (landscapes). The capability to infer variations in geometrical and physical properties across the inspected surfaces or volumes is the unifying factor of these techniques, allowing scientists to discover new historical sites or to image their spatial extent and material features at different scales, from landscape to artifact. This first part concentrates on the micro-scale, i.e., inspection, study and characterization of small objects (ancient papers, paintings, statues, archaeological findings, architectural elements, etc.) from surface to internal properties.peer-reviewe

Review of InfraRed Thermography and Ground-Penetrating Radar applications for building assessment

The first appearance of concern for the good condition of a building dates back to ancient times. In recent years, with the emergence of new inspection technologies and the growing concern about climate change and people’s health, the concern about the integrity of building structures has been extended to their analysis as insulating envelopes. In addition, the growing network of historic buildings gives this sector special attention. Therefore, this study presents a comprehensive review of the application of two of the most common and most successful Non-Destructive Techniques (NDTs) when inspecting a building: InfraRed Thermography (IRT) and Ground-Penetrating Radar (GPR). To the best knowledge of the authors, it is the first time that a joint compilation of the state-of-the-art of both IRT and GPR for building evaluation is performed in the same work, with special emphasis on applications that integrate both technologies. The authors briefly explain the performance of each NDT, along with the individual and collective advantages of their uses in the building sector. Subsequently, an in-depth analysis of the most relevant references is described, according to the building materials to be studied and the purpose to be achieved: structural safety, energy efficiency and well-being, and heritage preservation. Then, three different case studies are presented with the aim of illustrating the potential of the combined use of IRT and GPR in the evaluation of buildings for the purposes defined. Last, the final remarks and future lines are described on the application of these two interesting inspection technologies in the preservation and conservation of the building sector.European Union Next GenerationEU/PRTRAgencia Estatal de Investigación | Ref. PDC2021-121239-C32Agencia Estatal de Investigación | Ref. RYC2019-026604-

The Use of Ground Penetrating Radar and Microwave Tomography for the Detection of Decay and Cavities in Tree Trunks

Acknowledgements This paper is dedicated to the memory of Jonathan West; a friend, a colleague, a forester, a conservationist and an environmentalist, who died following an accident in the woodland that he loved.Peer reviewedPublisher PD

Close-Range Sensing and Data Fusion for Built Heritage Inspection and Monitoring - A Review

Built cultural heritage is under constant threat due to environmental pressures, anthropogenic damages, and interventions. Understanding the preservation state of monuments and historical structures, and the factors that alter their architectural and structural characteristics through time, is crucial for ensuring their protection. Therefore, inspection and monitoring techniques are essential for heritage preservation, as they enable knowledge about the altering factors that put built cultural heritage at risk, by recording their immediate effects on monuments and historic structures. Nondestructive evaluations with close-range sensing techniques play a crucial role in monitoring. However, data recorded by different sensors are frequently processed separately, which hinders integrated use, visualization, and interpretation. This article’s aim is twofold: i) to present an overview of close-range sensing techniques frequently applied to evaluate built heritage conditions, and ii) to review the progress made regarding the fusion of multi-sensor data recorded by them. Particular emphasis is given to the integration of data from metric surveying and from recording techniques that are traditionally non-metric. The article attempts to shed light on the problems of the individual and integrated use of image-based modeling, laser scanning, thermography, multispectral imaging, ground penetrating radar, and ultrasonic testing, giving heritage practitioners a point of reference for the successful implementation of multidisciplinary approaches for built cultural heritage scientific investigations

Structural Assessment via Ground Penetrating Radar at the Consoli Palace of Gubbio (Italy)

Ground Penetrating Radar (GPR) is a flexible and cost-effective tool for performing structural integrity assessment and quick damage evaluation of manmade structures, including cultural heritage (CH) assets. In this context, this paper deals with the usefulness of GPR surveys enhanced by the use of a Microwave Tomographic data processing approach as a methodology for the diagnosis and monitoring of CH exposed to climate events and natural hazards. Specifically, the paper reports on the results of a measurement campaign carried out at the Loggia of the Consoli Palace of Gubbio (Italy). These results allowed us to increase our knowledge of the architecture of the surveyed zones and their structural hazards