1887
Volume 22, Issue 1
  • ISSN: 1569-4445
  • E-ISSN: 1873-0604
PDF

Abstract

Abstract

The renaissance botanical garden of ‘El Bosque’ in Béjar (Salamanca, Spain) presents a pond bounded by a dam in its western part. The latter is formed by two masonry walls interconnected by buttresses. Cubic spaces in between are filled with a variable grain‐size material (silty sand) that allows limited water flow. In recent years, the southern part of the dam has experienced localized and random subsidence that jeopardizes the entrance to part of the garden. To regain access, a proper and reliable diagnosis of the origin, magnitude and relevance of the subsidence must be made. In this regard, we have undertaken a microgravity survey in the dam area to identify places with an anomalous distribution of the filling material in order to foresee further sinking or potential collapsing areas. The precise positioning (2 mm resolution) and accurate terrain correction needed in this kind of high‐resolution gravity surveys (points every 1.5 m) were achieved by creating a detailed digital terrain model (cm resolution) with a remotely piloted aircraft. In addition, we performed three electric resistivity tomography (ERT) profiles at different levels of the garden: (i) on the dam itself; (ii) right on the foot of the dam and parallel to it (5 m below and ∼17 m to the W); and (iii) a bit farther, but also parallel to the dam (8 m below and ∼27 m to the W). The ERT profiles identified high conductivity in water‐saturated areas and determined the paths that rainfall and pond's seepage water follow in the dam and its underground, formed by granites. The geophysical studies were paired with geotechnical analyses of the sunk materials. The study concluded that the thinnest fraction of the dam's filling material (i.e., silts) is being washed away, leaving behind sand with less density and stability, susceptible to collapse. Thus, the observed sinking is related to soil piping, that is to soil internal erosion and compaction issues that force the soil material to re‐adjust geometrically and volumetrically.

Loading

Article metrics loading...

/content/journals/10.1002/nsg.12283
2024-01-17
2024-04-27
Loading full text...

Full text loading...

/deliver/fulltext/nsg/22/1/nsg12283.html?itemId=/content/journals/10.1002/nsg.12283&mimeType=html&fmt=ahah

References

  1. AENOR . (1999) Standard test methods for geotechnical tests (soils). Madrid, Spain: Spanish Association Of Standardization And Certification (In Spanish).
    [Google Scholar]
  2. Arenas, R., Farias, P., Gallastegui, G., Gil Ibarguchi, I., González Lodeiro, F., Klein, E., et al. (1988) Características geológicas y significado de los dominios que componen la Zona de Galicia‐Trás‐os‐ Montes. Simposio sobre Cinturones Orogénicos. In: Simposio sobre cinturones orogénicos. II cogreso Geológico De España. Madrid, Spain: SGE, pp. 75–84.
    [Google Scholar]
  3. ASTM . (2011) D2487 standard practice for classification of soils for engineering purposes (unified soil classification system). West Conshohocken: ASTM International.
    [Google Scholar]
  4. ASTM . (2010) D1557 standard test methods for laboratory compaction characteristics of soil using modified effort. West Conshohocken: ASTM International.
    [Google Scholar]
  5. Bendahmane, F., MarotD. & AlexisA. (2008) Experimental parametric study of suffusion and backward erosion. Journal of Geotechnical and Geoenvironmental Engineering, 134(1), 57–67.
    [Google Scholar]
  6. Carbone, D. & Greco, F. (2007) Review of microgravity observations at Mt. Etna: a powerful tool to monitor and study active volcanoes. Pure and Applied Geophysics, 164(4), 769–790. https://doi.org/10.1007/s00024‐007‐0194‐7
    [Google Scholar]
  7. Chapuis, R.P. (1992) Similarity of internal stability criteria for granular soils. Canadian Geotechnical Journal, 29(4), 711–713.
    [Google Scholar]
  8. Debeglia, N., Bitri, A. & Thierry, P. (2006) Karst investigations using microgravity and MASW; application to Orléans, France. Near Surface Geophysics, 4(4), 215–225. https://doi.org/10.3997/1873‐0604.2005046
    [Google Scholar]
  9. Díez Balda, M.A. (1986) El Complejo esquisto‐ grauvaquico, las series paleozoicas y la estructura hercinica al sur de Salamanca. Salamanca, Spain: Universidad de Salamanca.
    [Google Scholar]
  10. Díez Balda, M.A., Martínez Catalán, J.R. & Ayarza, P. (1995) Syn‐collisional extensional collapse parallel to the orogenic trend in a domain of steep tectonics: the Salamanca Detachment Zone (Central Iberian Zone, Spain). Journal of Structural Geology, 17(2), 163–182. https://doi.org/10.1016/0191‐8141(94)E0042‐W
    [Google Scholar]
  11. Ezersky, M., Bruner, I., Keydar, S., Trachtman, P. & Rybakov, M. (2006) Integrated study of the sinkhole development site on the western shores of the Dead Sea using geophysical methods. Near Surface Geophysics, 4(5), 335–343. https://doi.org/10.3997/1873‐0604.2006007.
    [Google Scholar]
  12. Fais, S., Radogna, P.V., Romoli, E., Matta, P. & Klingele, E.E. (2015) Microgravity for detecting cavities in an archaeological site in Sardinia (Italy). Near Surface Geophysics, 13(5), 495–502. https://doi.org/10.3997/1873‐0604.2015036.
    [Google Scholar]
  13. Fannin, R.J. & Slangen, P. (2014) On the distinct phenomena of suffusion and suffosion. Géotechnique Letters, 4(4), 289–294.
    [Google Scholar]
  14. Farias, P., Gallastegui, G., González Lodeiro, F., Marquinez, J., Martín‐Parra, L.M., Martínez Catalán, J.R. et al. (1987) Aportaciones al conocimiento de la litoestratigrafia y estructura de Galicia Central. Memórias Da Faculdade de Ciências, Universidade Do Porto, 1, 411–431.
    [Google Scholar]
  15. Gibbs, H.J. (1961) Properties with divide loess and dense uncement of the soils. In: Earth Laboratory report EM‐658, bureau of reclamation. Washington DC: US Department of Interior.
  16. Gimenez, M., Martínez, P., Ruíz, F., Introcaso, A. & La Vecchia, J. (2005) Weathering zone determination in the province of Rio Negro, Argentina, with high resolution gravimetry. Near Surface Geophysics, 3(2), 103–109. https://doi.org/10.3997/1873‐0604.2005005.
    [Google Scholar]
  17. González de Vallejo, L.I., Ferrer, M., Ortuño, L. & Oteo, C. (2002) Ingeniería geológica. London: Pearson Educación.
    [Google Scholar]
  18. Hojat, A., Arosio, D., Ivanov, V.I., Loke, M., Longoni, L., Papini, M. et al. (2020) Quantifying seasonal 3D effects for a permanent electrical resistivity tomography monitoring system along the embankment of an irrigation canal. Near Surface Geophysics, 18, 427–443.
    [Google Scholar]
  19. Julivert, M., Fontboté, M., Ribeiero, A. & Conde, L.E. (1972) Mapa tectónico de la Península Ibérica y Baleares Notas Incluye mapa: Unidades estructurales de la Península Ibérica. Escala 1 : 1.000.000. Madrid, Spain: Instituto Geológico y Minero de España.
  20. Kenney, T., & Lau, D. (1985) Internal stability of granular filters. Canadian Geotechnical Journal, 22(2), 215–225.
    [Google Scholar]
  21. Kovács, G. (1981) Seepage hydraulics. Amsterdam, The Netherlands: Elsevier Scientific Publishing Co.
    [Google Scholar]
  22. Lopez Sopeña, F., Lillo Ramos, F.J., Díez Montes, A., Olive Dado, A. & Rubio Campos, J.C. (1994) Memoria explicativa de la hoja n, vol. 553. Madrid, Spain: Instituto Geológico y Minero de España, pp. 5000. Béjar. Plan Magna, IGME.
    [Google Scholar]
  23. Martínez Catalán, J.R., Díez Balda, M.A., Escuder Viruete, J., Villar Alonso, P., Ayarza, P., Gonalez Clavijo, E. et al. (2019) Cizallamientos dúctiles de escala regional en la Provincia de Salamanca. In: Diaz AzpirozM., Exposito RamosI., Llana FúnezS. & Bauluz LázaroB. (Eds.) Geo‐Guias: Rutas Geológicas por la Península Ibérica, Canarias, Sicilia y Marruecos. Salamanca, Spain: Sociedad Geológica de España, pp. 109–118.
    [Google Scholar]
  24. Matte, P. (2001) The Variscan collage and orogeny (480–290 Ma) and the tectonic definition of the Armorica microplate: a review. Terra Nova, 13(2), 122–128. http://onlinelibrary.wiley.com/doi/10.1046/j.1365‐3121.2001.00327.x/full%5Cnpapers2://publication/uuid/85445613‐EAD8‐49D7‐AE4E‐704E3D282C36
    [Google Scholar]
  25. Muñoz Dominguez, J., Sánchez Santo, J.F., Sanz Belloso, J.C. (2009) El estanque de la villa renacentista El Bosque de Bejar, una presa holandesa en Castilla. In: Actas del Sexto Congreso Nacional de Historia de la Construcción, Valencia, Madrid, Spain: Juan de Herrera Institute, pp. 955–966.
  26. Nyquist, J.E., Freyer, P.A. & Toran, L. (2008) Stream bottom resistivity tomography to map ground water discharge. Ground Water, 46(4), 561–569. https://doi.org/10.1111/j.1745‐6584.2008.00432.x.
    [Google Scholar]
  27. Oli, I.C., Ahairakwem, C.A., Opara, A.I., Ekwe, A.C., Osi‐Okeke, I., Urom, O.O. et al. (2020) Hydrogeophysical assessment and protective capacity of groundwater resources in parts of Ezza and Ikwo areas, Southeastern Nigeria. International Journal of Energy and Water Resources, 5, 57–72. https://doi.org/10.1007/s42108‐020‐00084‐3
    [Google Scholar]
  28. Orfanos, C. & Apostolopoulos, G. (2011) 2D–3D resistivity and microgravity measurements for the detection of an ancient tunnel in the Lavrion area, Greece. Near Surface Geophysics, 9(5), 449–457. https://doi.org/10.3997/1873‐0604.2011024.
    [Google Scholar]
  29. Panisova, J., Pašteka, R., Papčo, J. & Fraštia, M. (2012) The calculation of building corrections in microgravity surveys using close range photogrammetry. Near Surface Geophysics, 10(5), 391–399. https://doi.org/10.3997/1873‐0604.2012034
    [Google Scholar]
  30. Taniguchi, M., Ishitobi, T., Burnett, W.C. & Wattayakorn, G. (2007) Evaluating ground water–sea water interactions via resistivity and seepage meters. Ground Water, 45(6), 729–735. https://doi.org/10.1111/j.1745‐6584.2007.00343.x
    [Google Scholar]
  31. de Vicente, G., Cunha, P.P., Muñoz‐Martín, A., Cloetingh, S.A. P.L., Olaiz, A. & Vegas, R. (2018) The Spanish–Portuguese Central System: an example of intense intraplate deformation and strain partitioning. Tectonics, 37(12), 4444–4469. https://doi.org/10.1029/2018TC005204
    [Google Scholar]
  32. Vidal Montes, R., Martinez‐Graña, A.M., Martínez Catalán, J.R., Ayarza, P. & Sánchez San Román, F.J. (2016) Vulnerability to groundwater contamination. SW Salamanca, Spain. Journal of Maps, 12, 147–155. https://doi.org/10.1080/17445647.2016.1172271.
    [Google Scholar]
  33. Vidal Montes, R., Martínez‐Graña, A.M., Martínez Catalán, J.R., Ayarza, P., Sánchez San Román, J. & Zazo, C. (2017) Integration of GIS, electromagnetic and electrical methods in the delimitation of groundwater polluted by effluent discharge (Salamanca, Spain): a case study. International Journal of Environmental Research and Public Health, 14(11), 1–14. https://doi.org/10.3390/ijerph14111369
    [Google Scholar]
  34. Zahorec, P., Pašteka, R., Papčo, J., Putiška, R., Mojzeš, A., Kušnirák, D. et al. (2021) Mapping hazardous cavities over collapsed coal mines: case study experiences using the microgravity method. Near Surface Geophysics, 19(3), 353–364. https://doi.org/10.1002/nsg.12139
    [Google Scholar]
  35. Zhou, Z.Q., Ranjit, P.G., & Li, S.C. (2015) Optimal models forparticle size distributions of granular soils. Proceeding of the InstitutionCivil Engineers‐Geotechnical Engineering, 169(1), 73–82. https://dx.doi.org/10.1680/jgreen.15.00075
    [Google Scholar]
  36. Zur, A. & Wiseman, G. (1973) A Study of collapse phenomena of an undisturbed loess. In: Proceeding of the eighth international conference on soil mechanics and foundation engineering, Moscow: URSS. pp. 265–269.
http://instance.metastore.ingenta.com/content/journals/10.1002/nsg.12283
Loading
/content/journals/10.1002/nsg.12283
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): 2D; ERT; gravity; sinkhole

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error