GPR measurements to identify cracks and textural arrangements in the altar wall of the 16th‐century Santa Maria Huiramangaro Church, Michoacán, Mexico

Abstract

A three‐dimensional ground‐penetrating radar survey was performed on the altar wall, which faced the risk of collapse, of a 16th‐century church in Michoacán, Mexico. The ground‐penetrating radar survey with high‐frequency antennas aimed to locate structural cracks and texture arrangements, the latter through the interpretation of the patterns in the electromagnetic data. The results indicate that the superficially visible cracks or fractures, except for the lateral ones at each end of the wall, disappear at a depth of between 15 and 25 cm. The lower part of the wall below a height of 3.97 m presents an area with multiple diffractions, which suggests that the masonry is made of ‘stone and mud’ and the tilt appears precisely where the adobe wall starts. Using 1500 and 900 MHz antennas, the identified texture of the wall shows at least three leaves or layers with diverse materials and a wooden beam embedded in the wall. Additionally, the survey near the church with a 200 MHz antenna supports the hypotheses that local construction materials were used here. The results inspire us to continue applying ground‐penetrating radar, a non‐destructive method, to diagnose the walls and structures of historical monuments before any intervention.

Non destructive diagnosis at the Brancacci Chapel, Church of Santa Maria del Carmine (Florence)

“…The GPR is a rapid data acquisition technique that offers observable results in high-resolution imaging [1,2], supplies information on monumental structures with acceptable limits of uncertainty, and helps identify hidden targets in the subsoil, for example, voids or cavities such as tombs or crypts [1,2,3] and walls or buried structures that are entirely invisible on the surface [ 1,2,3]. The GPR has also been used to assess the state of conservation of wooden structures and columns [3] and to identify fractures in walls and cavities [1,4,5]. In the case of frescoes, the GPR provides essential information to define the textural and structural conditions and alterations of the walls [5,6] which support the painting [7].…”

“…The GPR has also been used to assess the state of conservation of wooden structures and columns [3] and to identify fractures in walls and cavities [1,4,5]. In the case of frescoes, the GPR provides essential information to define the textural and structural conditions and alterations of the walls [5,6] which support the painting [7]. Interesting examples of GPR applications for walls and frescos hidden are also shown in [5].…”

“…In the case of frescoes, the GPR provides essential information to define the textural and structural conditions and alterations of the walls [5,6] which support the painting [7]. Interesting examples of GPR applications for walls and frescos hidden are also shown in [5].…”

Time-Lapse GPR Measurements to Monitor Resin Injection in Fractures of Marble Blocks

“…The GPR method has proved its ability as a valuable geophysical technique to enter the quarrying and construction industries to map the fractures at different stages: during exploration and extraction in quarries to reduce the production costs and wastes [6,7,[10][11][12][18][19][20], and for post-production demands to repair and restore the stones [21]. From various research studies that use the GPR method to study rock fractures, we can mention the theoretical models and laboratory experiments used to characterize rock discontinuities [18][19][20][21][22][23][24][25][26], in situ GPR surveys to detect fractures at different zones of quarries or in historical buildings [7,10,12,15,22,[27][28][29][30], and 3D GPR acquisitions for 3D reconstruction of the fractures and other features [11,12,[31][32][33][34]. Most of these studies are focused on the application of the GPR method to detect rock/stone fractures to optimize the quarrying activities and to preserve the constructions.…”

Detection and Characterization of Cracks in Highway Pavement with the Amplitude Variation of GPR Diffracted Waves: Insights from Forward Modeling and Field Data

“…In a homogeneous medium, the responses of the top and bottom of a single vertical crack in a GPR profile appear as two different diffraction hyperbolas [14,15]. Compared with the nether hyperbola, the upper hyperbola with an opposite-phase has a greater curvature and stronger amplitude, making it easy to identify the crack type and locate the top and bottom of the crack [16,17].…”