1887
Volume 5, Issue 5
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604

Abstract

ABSTRACT

The development of cracks and distortions caused by past seismic events compromised the integrity of the rose window of Troia Cathedral, one of the most precious Romanesque monuments in southern Italy. Ground‐penetrating radar (GPR) using high‐frequency antennae (mainly 1500 MHz) was selected from among various non‐destructive testing methods for its high‐resolution imaging to scan the internal structure of the various architectural elements of the wheel window: the decimetre‐diameter columns constituting the rays, the ring decorated with intersecting arched ribwork and the surrounding circular ashlar curb. GPR was employed in the classical continuous reflection mode, moving the antennae manually along the architectural elements and paying exceptional care in the acquisition and processing stages to avoid positioning errors. Indeed, the challenging aspects of this case study were the geometrical complexity and small dimensions of the structural elements, causing many logistic/coupling problems. In spite of this, through proper interpretation techniques, based on signal analysis (presence of reflections and diffractions, velocity and attenuation variations) and correlation with features detected by visual inspection of the external surfaces, the GPR survey provided useful information on the internal structure of the rose window, detecting fractures and the boundaries of previously restored parts and locating hidden metallic components connecting the architectural elements. Information on the internal structure and spatial distribution of metallic junctions was essential for gaining insight into building techniques in order to discriminate between restoration strategies which may require either total or partial dismantling of the rose window. GPR results provided crucial evidence in favour of one of the (conflicting) hypotheses about the original building techniques, leading to the selection of partial dismantling as the most suitable restoration strategy. Analysis of measurements revealed the potential of GPR in the field of cultural heritage restoration, even in those cases characterized by complex geometry, structural brittleness and logistic difficulties, such as that discussed in this paper.

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2007-03-01
2024-04-16
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References

  1. BasileV., CarrozzoM.T., NegriS., NuzzoL., QuartaT. and VillaniA.V.2000. A ground‐penetrating radar survey for archaeological investigations in an urban area (Lecce, Italy).Journal of Applied Geophysics44, 15–32.
    [Google Scholar]
  2. Belli D’EliaP.1998. Per la storia di Troia: dalla chiesa di S. Maria alla cattedrale.Vetera Christianorum25, 605–620.
    [Google Scholar]
  3. BindaL., LenziG. and SaisiA.1998. NDE of masonry structures: use of radar tests for the characterisation of stone masonries.NDT&E International31, 411–419.
    [Google Scholar]
  4. CaliaA.2004. I materiali lapidei costituenti il rosone. In: Indagini diagnostiche e indicazioni progettuali per il restauro della facciata e del rosone della cattedrale di Troia. Technical report (D. Liberatore and N. Masini).
    [Google Scholar]
  5. CardarelliE.1995. 3D tomography of some pillars of the Coliseum.Bollettino di Geofisica Teorica ed Applicata37, 267–275.
    [Google Scholar]
  6. CardarelliE., GodioA., MorelliG., SambuelliL., SantaratoG. and SoccoL.V.2002. Integrated geophysical surveys to investigate the Scarsella vault of St. John’s Baptistery in Florence.The Leading Edge67, 467–470.
    [Google Scholar]
  7. ChianeseD., D’EmilioM.G., Di SalviaS., LapennaV., RagostaM. and RizzoE.2004. Magnetic mapping, ground penetrating radar surveys and magnetic susceptibility measurements for the study of the archaeological site of Serra di Vaglio (Southern Italy).Journal of Archaeological Science31, 633–643.
    [Google Scholar]
  8. ColeK.S. and ColeR.H.1941. Dispersion and absorption in dielectrics.Journal of Chemical Physics9, 341–351.
    [Google Scholar]
  9. ConyersL.B. and GoodmanD.1997. Ground‐penetrating Radar – An Introduction for Archaeologists. Alta Mira Press, Walnut Creek.
    [Google Scholar]
  10. DavisJ.L. and AnnanA.P.1989. GPR for high‐resolution mapping of soil and rock stratigraphy.Geophysical Prospecting37, 531–551.
    [Google Scholar]
  11. DebyeR.1929. Polar Molecules. Dover Publications, Inc., Mineola, NY.
    [Google Scholar]
  12. FranceseR., GalgaroA. and GrespanA.2004. Venice channel side‐wall assessment with GPR technique ‐ a case study.Journal of Applied Geophysics56, 31–40.
    [Google Scholar]
  13. JonscherA.K.1977. The universal dielectric response.Nature267, 673–679.
    [Google Scholar]
  14. LiberatoreD. and MasiniN.2004. Indagini diagnostiche e indicazioni progettuali per il restauro della facciata e del rosone della cattedrale di Troia. Technical report.
    [Google Scholar]
  15. MaierhoferC. and LeipoldS.2001. Radar investigation of masonry structures.NDT&E International34, 139–147.
    [Google Scholar]
  16. MaierhoferC., LeipoldS. and WiggenhauserH.1998. Investigation of the influence of moisture and salt content on the dielectric properties of brick materials using radar.Proceedings of the 7th International Conference on Ground Penetrating Radar (GPR), Kansas, USA, pp. 477–84.
    [Google Scholar]
  17. MaierhoferC. and WöstmannJ.1998. Investigation of dielectric properties of brick materials as a function of moisture and salt content using a microwave impulse technique at very high frequencies.NDT & E International31, 259–263.
    [Google Scholar]
  18. McCannD.M. and FordeM.C.2001. Review of NDT methods in the assessment of concrete and masonry structures.NDT&E International34, 71–84.
    [Google Scholar]
  19. PiconeR.2000. ‘Ristauro’ e de‐restauro. Il caso della cattedrale di Troia in Puglia. In: Restauro Dalla Teoria alla Prassi (ed. S.Casiello), pp. 76–102, Electa Napoli.
    [Google Scholar]
  20. PiroS., GoodmanD. and NishimuraY.2003. The study and characterization of Emperor Traiano’s Villa (Altopiani di Arcinazzo, Roma) using high‐resolution integrated geophysical surveys.Archaeological Prospection10, 1–25.
    [Google Scholar]
  21. RanalliD., ScozzafavaM. and TalliniM.2004. Ground penetrating radar investigations for the restoration of historic buildings: the case study of the Collemaggio Basilica (L’Aquila, Italy).Journal of Cultural Heritage5, 91–99.
    [Google Scholar]
  22. RobertA.1998. Dielectric permittivity of concrete between 50 MHz and 1 GHz and GPR measurements for building materials evaluation.Journal of Applied Geophysics40, 89–94.
    [Google Scholar]
  23. SambuelliL., GodioA., GuoT.J. and SoccoL.V.1998. Laboratory determination of the dielectric permittivity of building stones in the 0.2–6 GHz band.IV Meeting of the Environmental and Engineering Geophysical Society (European Section), Barcelona, Spain, Expanded Abstracts, pp. 477–480.
    [Google Scholar]
  24. SambuelliL., SoccoL.V. and BrecciaroliL.1999. Acquisition and processing of electric, magnetic and GPR data on a Roman site (Victimulae, Salussola, Biella).Journal of Applied Geophysics41, 189–204.
    [Google Scholar]
  25. SandmeierK.J.2004. REFLEXW, Version 3.0.8 Windows™ 9x/NT‐program for the processing of seismic, acoustic or electromagnetic reflection, refraction and transmission data. Copyright 1998‐2004 by K. J.Sandmeier , ZipserStraße 1, D‐ 76227 Karlsruhe, Germany. www.sandmeier‐geo.de
    [Google Scholar]
  26. ScottM., RezaizadehA., DelahazaA., SantosC.G., MooreM., GraybealB. and WasherG.2003. A comparison of nondestructive evaluation methods for bridge deck assessment.NDT&E International36, 245–255.
    [Google Scholar]
  27. SerenS., Eder‐HinterleitnerA., NeubauerW. and GrohS.2004. Combined high‐resolution magnetics and GPR surveys of the Roman town of Flavia Solva.Near Surface Geophysics2, 63–68.
    [Google Scholar]
  28. ShenL.C., SavreW.C., PriceJ.M. and AthavaleK.1985. Dielectric properties of reservoir rocks at ultra‐high frequencies.Geophysics50, 692–704.
    [Google Scholar]
  29. TaherianM.R., KenyonW.E. and SafinyaK.A.1990. Measurement of dielectric response of water‐saturated rocks.Geophysics55, 1530–1541.
    [Google Scholar]
  30. The MathWorks
    The MathWorks , 2002. MATLAB Version 6.5.0.
    [Google Scholar]
  31. ToppG.C., DavisJ.L. and AnnanA.P.1980. Electromagnetic determination of soil water content: measurements in coaxial transmission lines.Water Resources Research16, 574–582.
    [Google Scholar]
  32. UlriksenP.1982. Application of impulse radar to civil engineering. PhD thesis, Lund University of Technology, Lund, Sweden.
    [Google Scholar]
  33. VaccaneoD., SambuelliL., MariniP., TasconeR. and OrtaR.2004. Measurement system of complex permittivity of ornamental rocks in L frequency band.IEEE Transactions on Geoscience and Remote Sensing42, 2490–24.
    [Google Scholar]
  34. ValleS. and ZanziL.1998. Traveltime radar tomography for NDT on masonry and concrete structures.European Journal of Environmental Engineering Geophysics2, 229–246.
    [Google Scholar]
  35. ValleS., ZanziL. and RoccaF.1999. Radar tomography for NDT: comparison of techniques.Journal of Applied Geophysics41, 259–269.
    [Google Scholar]
  36. Wensink
    Wensink1993. Dielectric properties of wet soils in the frequency range 1–3000 MHz.Geophysical Prospecting41, 671–696.
    [Google Scholar]
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