1887
Volume 37 Number 1
  • E-ISSN: 1365-2478

Abstract

A

Underground gravity observations in deep coal mines using the conventional gravity meters Worden (type Master) and LaCoste‐Romberg (model D), both of which have been adapted to the fire damp regulations, can be accurate to ± 10 and ± 3 μgal, respectively. For underground determination of the vertical gradient of gravity the LaCoste‐Romberg meter is used together with a specially designed measuring tower. Using this euipment an accuracy in tower gradient observations of ± 30 E was obtained.

To apply the equipment to precision gravity observations in underground situations an additional correction, i.e. a gallery correction, is needed. High accuracy in correction is achieved by a new method of three‐dimensional modelling. The gravity effect is computed for bodies with a surface approximated by triangular elements, which are generated from corner points of the body. The combination of gallery correction with tower gradient data leads to a new method for density determination. It offers the possibility of horizontal instead of vertical density profiling.

To demonstrate the effectiveness of the developments in underground observations the localization of a pump room is presented. Microgravity and tower gradient observations were carried out to detect the cavity. The horizontal gradient was also calculated to give a more reliable location.

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2006-04-27
2020-04-02
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References

  1. Bližkowský, M.1979. Processing and applications in microgravity surveys. Geophysical Prospecting27, 848–861.
    [Google Scholar]
  2. Butler, D.K.1984. Microgravimetric and gravity gradient techniques for detection of subsurface cavities. Geophysics49, 1084–1096.
    [Google Scholar]
  3. Casten, U. and Fajklewicz, Z.1986. Die Überwachung gebirgsschlaggefährdeter Bereiche mit der Mikrogravimetrie. Glückauf-Forschungshefte47, 290–295.
    [Google Scholar]
  4. Domzalski, W.1954. Gravity measurements in a vertical shaft. Transactions of the Institute of Mining and Metallurgy63, 429–445.
    [Google Scholar]
  5. Dresen, L., Fajklewicz, Z., Götze, H.‐J., Sommer, H. and te Kook, J.1981. Die Ortung oberflächennaher Hohlräume durch die Bestimmung des Vertikalgradienten der Schwere. Glückauf-Forschungshefte42, 84–88.
    [Google Scholar]
  6. Fajklewicz, Z.1976. Gravity vertical gradient measurements for the detection of small geologic and antropogenic forms. Geophysics41, 1016–1030.
    [Google Scholar]
  7. Fajklewizc, Z.1983. Rock‐burst forecasting and genetic research in coal mines by micro‐gravity method. Geophysical Prospecting31, 748–765.
    [Google Scholar]
  8. Fajklewicz, Z.1986. Origin of the anomalies of gravity and its vertical gradient over cavities in brittle rock. Geophysical Prospecting34, 1233–1254.
    [Google Scholar]
  9. Götze, H.‐J.1984. Über den Einsatz interaktiver Computergraphic im Rahmen 3‐dimensionaler Interpretationstechniken in Gravimetrie und Magnetik. HabiliBioklimatologie A 27, 195–215.
    [Google Scholar]
  10. Götze, H.‐J.1984. Über den Einsatz interaktiver Computergraphic im Rahmen 3‐dimensionaler Interpretationstechniken in Gravimetrie und Magnetik. Habili‐tationsschrift, Technische Universität Clausthal.
    [Google Scholar]
  11. Hanemann, K.D. and Militzer, H.1985. Ein neues Verfahren zur Streckenreduktion in der Untertagegravimetrie. 3. Int. Alpengravimetrie‐Koll., Leoben 1983. Berichte über den Tiejbau der Ostalpen, H. 12, Zentralanstalt für Meteorologie und Geodynamik, Wien , 195–212.
    [Google Scholar]
  12. Hearst, J.R. and Carlson, R.C.1982. Measurement and analysis of gravity in boreholes. Developments in Geophysical Exploration Methods, A. A.Fitch (ed.), Vol. 3, 269–303. Applied Science Publishers Ltd.
    [Google Scholar]
  13. Hinze, W.J., Bradley, J.W. and Brown, A.R.1978. Gravimeter survey in the Michigan Basin Deep borehole. Journal of Geophysical Research83, 5864–5868.
    [Google Scholar]
  14. Hussain, A.1983. Underground gravity surveys. Development in Geophysical Exploration Methods, A. A.Fitch (ed.), Vol. 5, 35–63. Applied Science Publishers Ltd.
    [Google Scholar]
  15. Jung, H.1939. Dichtebestimmung im anstehenden Gestein durch Messungen der Schwere‐beschleunigung in verschiedenen Tiefen unter Tage. Zeitschrift für Geophysik15, 56–65.
    [Google Scholar]
  16. Lawson, C.L.1972. Generation of triangular grid with application to contour plotting, Technical Memorandum 299, Sec. 914, Jet Propulsion Laboratory, California Institute of Technology, Pasadena , California .
    [Google Scholar]
  17. Nettleton, L.L.1976. Gravity and Magnetics in Oil Prospecting. McGraw‐Hill Book Co.
    [Google Scholar]
  18. Owen, T.E.1983. Detection and mapping of tunnels and caves. Developments in Geophysical Exploration Methods, A. A.Fitch (ed.), Vol. 5, 161–258. Applied Science Publishers Ltd.
    [Google Scholar]
  19. Sommer, H.1983. Untersuchungen zur Ortung oberflächennaher Hohlräume mit gravi‐metrischen Verfahren. Berichte des Instituts für Geophysik der Ruhr‐Universität Bochum , Reihe A, Nr. 12.
    [Google Scholar]
  20. Talwani, M., Worzel, J.L. and Landisman, M.1959. Rapid gravity computations for two‐dimensional bodies with application to the Mendocino submarine fracture zone. Journal of Geophysical Research64, 49–59.
    [Google Scholar]
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