THE USE OF GROUND PENETRATING RADAR FOR THE ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING THE USE OF GROUND PENETRATING RADAR FOR THE ASSESSMENT OF THE CONSERVATION STATE OF AN HISTORIC BUILDING (original) (raw)
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Structural Control and Health Monitoring
Combined non-destructive techniques are applied in the study of a historical building in Barcelona. Santa Maria del Mar is a magnificent Mediterranean gothic church built between 1329 and 1383. Two of the most important characteristics of this building are the slender columns and the almost flat rooftop. This structure, used to create a visual impression of a unique space, transmits high loads to the tall columns. Previous to restoration, vaults, roofs, and columns were extensively assessed with non-destructive tests, in order to improve the knowledge of those structures. This information will be used in further simulations to analyse load distributions at each part of the structure. Ground and floor were also studied. The analysis of the columns was based on groundpenetrating radar (GPR) surveys and on seismic tomography. Finally, the dynamic behaviour of the structure was determined by seismic monitoring of the main nave and the bell tower. Results obtained at the radar survey highlight the existence of unexpected anomalies in homogeneous materials, supporting the hypothesis of an inner structure between arches and roof composed by hollow elements. Seismic tomography defined the inner geometry of the columns and detected some damage or lower quality stone in various zones. Seismic monitoring established the perfect junction between the bell tower and the main nave. GPR survey on the floor allowed detecting a large number of graves, and some images suggest the existence of large underground walls and some of the foundations of the main façade.
Performance of Ground Penetrating RADAR Technique in Assessment of Heritage Structures
Heritage structures are important for its culture and pride. They are historic evidences. There is a need to inspect and maintain them. Inspecting of structure by taking the samples of the structure may disturb the view and strength of the structure and more over the complete detail of the structure may not be found by taking few samples. Importance of non-destructive testing has been developing to solve this problem. There are many non-destructive testing methods evolved in last few decades. The usage of those methods depends on the accessibility and accuracy of those methods. To reduce the error and get more data RADAR concept is being developed. The GPR (Ground Penetrating Radar) used here gives the signal images only. To study and compare, data of signals of different possible errors are required as reference. An acoustic wall (similar to most of heritage structures in India) is build inducing all the possible defects. The data from GPR shall be considered as reference for such experiments done on heritage structures. The signal processing is done using MATLAB, RADAN, and SIR software. Key Words: Acoustic stones, heritage buildings, GPR (of frequencies 2.6GHz, 1.6GHz, 900MHz, 400MHz), RADAN-7 and MATLAB. International Research Journal of Engineering and Technology (IRJET) e
International Journal of Conservation Science , 2022
Non-invasive surveys are more and more frequently used in historical heritage studies because they allowed to non-destructive examination of the state of the preservation of the historical monuments. Groundpenetrating radar (GPR) method belongs to them. The most important problem limiting the use of GPR on sites with historical architecture is presence of thick accumulations of rubble, modern infrastructure elements and very often dense plan cover. Despite these restrictions, correctly performed GPR survey may deliver very important data related to the layout and also subsurface stratigraphy of studied architectural relicts as it is presented by GPR survey of the renaissance Wyszyna Castle, located in Central Poland. Field was in next steps compared and combined with available architectural, historical and archaeological records. In the finale stage, particular datasets were performed to recreate the layout of the Wyszyna Castle. This became the basis for reconstruction proposed herein in form of a scaled 3D model of this monument. Authors are convinced that complex attitude presented in this work should become a standard in architectural studies with application of geophysical methods.
Metrology for Archaeology and Cultural Heritage, pp. 350–354, 2023
The basilica of Santa Croce in Lecce is a baroque church internationally well known; the starting point for this research was the evidence that some structures of the façade are more damaged and present signs of subsidence. The possible causes of damages can be: i) buried structures or subsurface anomalies; ii) not suitable microclimatic conditions; iii) deposition of pollutants. In order to study the first cause of damage geophysical survey, using groundpenetrating radar (GPR) was performed. This allow to obtain information on buried structures or to locate and identify anomalies related to a restoration intervention carried out in the 80s.
Open Journal of Geology, 2012
A comprehensive Ground Penetration Radar (GPR) investigations and hazard assessment for the rehabilitation and strengthening of Habib Sakakini's Palace in Cairo is presented herein, which is considered one of the most significant architectural heritage sites in Egypt. The palace located on an ancient water pond at the eastern side of Egyptian gulf besiding Sultan Bebris Al-Bondoqdary mosque is a place also called "Prince Qraja al-Turkumany pond". That pond had been filled down by Habib Sakakini at 1892 to construct his famous palace in 1897. The integrated geophysical survey of the palace allowed the identification of several targets of potential archaeological and geotechnical engineering interest buried in fill and silty clay in the depth range between 100-700 cm. the methodological development focused on Multi-Fold (MF) Ground Penetrating Radar (GPR) imaging and subsurface characterization based on integrated velocity and attenuation analysis. Eight hundred sqm of Ground penetration Radar (GPR) profiling have been conducted to monitor the subsurface conditions. 600 meters are made in the surrounding area of the Palace and 200 sqm at the basement. The aim is to monitor the soil conditions beneath and around the Palace and to identify potential geological discontinuities, or the presence of faults and cavities. A suitable single and dual antenna are used (500-100 MHZ) is used to penetrate the desired depth of 7 meters (ASTM D6432). The GPR is used also detect the water table. At the building basement the GPR is used to identify the foundation thickness and soil-basement interface. As well as the inspection of cracks in some supporting columns, piers and masonry walls. The GPR also was used to investigate the floors and ceilings conditions and structural mapping. The results were validated by the geotechnical and structural surveys. All these results together with the seismic hazard analysis will be used for the complete analysis of the palace in the framework of the rehabilitation and strengthening works foreseen in a second stage.
The Bayon Complex in the Angkor heritage site, Cambodia, has been damaged by weathering. To plan its long-term preservation, it is essential to investigate its internal structure and the degree of damage within the masonry monument. This study shows results of ground-penetrating radar (GPR) and electrical exploration surveys, and an interpreted section of the internal structure and moisture distribution in the masonry monument. The GPR can detect boundaries between stone blocks and between stone blocks and compacted soil. Electrical resistivity can indicate moisture distribution with high reliability in combination with GPR sections. The top surface zone of the terrace structure of this monument is composed of three layers of stone blocks, and the zone below a depth of 55-60 cm is composed of compacted soil. Rainwater penetrates into the terrace through gaps between the stone blocks and drains from vertical walls through cavities in the top part of the compacted soil. Damaged areas are limited to a part of the terrace, and a large area has remained in good condition. This study shows that a combination of electrical resistivity and GPR data is useful for investigating the internal structures and classifying the degree of damage to old stone structures.
Structural Assessment via Ground Penetrating Radar at the Consoli Palace of Gubbio (Italy)
Remote Sensing
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.
The presence of particular microclimatic conditions inside monumental buildings is responsible for bio-deterioration processes. In many cases, efflorescence and moulds are visible on the facades of several monuments of historical importance. In many other cases, the effects of decay processes are not visible, thus making difficult the diagnosis and the consequent setup of effective rehabilitation and preservation interventions, especially in the presence of a complex geometry and/or a large variability of construction materials. In such cases, a valuable contribution could be provided by geophysical methods (such as electrical resistivity, electromagnetic conductivity, ground-penetrating radar (GPR), etc), which have been proved to be successful tools for sub-surface investigation and characterization of historical buildings. In old monumental buildings, the masonry structures frequently exhibit cracks, voids, detachments and high moisture contrasts that can give rise to reflection events in radar signals. However, the complexity of the geometry and the structural heterogeneity that characterize these old structures often make the GPR results difficult to analyse and interpret. In particular, the spatial variation in GPR signal attenuation can provide important information about the electrical properties of the investigated materials that, in turn, can be used to assess the physical parameters associated with damage. In this paper, we propose an approach that analyses the data in the form of 'frequency maps' to evidence absorption losses probably linked to higher moisture content. Two real case histories back up the proposed method.