1887
Volume 41 Number 1
  • E-ISSN: 1365-2478

Abstract

A

The use of the gravity method to predict rock bursts in mines is based on the relationship between the development of a dilatancy process in the exploited rock mass and the time‐dependent gravity anomalies induced by this phenomenon. The differences between successive observations of anomalies and the time behaviour of their trend amplitudes as precursors of preceding changes of rock stability are interpreted. The centres of zones of induced rock density variation are determined by computing the position of singular points of the differences between anomalies.

Two gravity surveys have been carried out in the Radbod coal mine (Germany). The first survey took place at the level of the Dickebank seam (depth 1030 m), the second in the Sonnenschein seam (depth 1090 m). The observations were made with Worden and LaCoste‐Romberg (D‐type) gravimeters. The differences between successive anomalies were less than 100 μGal.

In the case of the Dickebank seam, the position of singular points demonstrates the effect of two approaching longwalls on a previously mined‐out seam and on the gallery in which the gravity observations were made. In the case of the Sonnenschein seam, the trend amplitudes show distinct variations in the formation of the approaching longwall below the edges of all previously mined‐out seams. In particular, the effect of a remnant pillar has caused the largest gravity gradients. This result corresponds to the existence of a zone of rock‐burst hazard known from test drilling. The computed singular points are grouped together under the remnant pillar indicating two local hazard zones.

Both results, the observed development of rock instability with time and the information about the position of the disturbed rock mass relative to the mine workings, are of importance, subsurface gravity surveying can therefore be a valuable tool for predicting rock‐bursts.

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2006-04-27
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References

  1. Algermissen, S.T.1961. Underground and surface gravity survey, Leadwood, Missouri. Geophysics15, 158–168.
    [Google Scholar]
  2. Bieniawski, Z.T.1967. Mechanism of brittle fracture of rocks. International Journal of Rock Mechanics and Mining Sciences4, 395–430.
    [Google Scholar]
  3. Brace, W.F.1978. Volume changes during fracture and frictional sliding – a review. Pageoph116, 603–614.
    [Google Scholar]
  4. Brace, W.F., Paulding, B.W. and Scholz, C.1966. Dilatancy in the fracture of crystalline rocks. Journal of Geophysical Research71, 3939–3953.
    [Google Scholar]
  5. Casten, U.1982. Gravimetrische Untersuchungen zur Erfassung bergbaubedingter Dichteänderungen im Gebirge. Glückauf118, 653–657.
    [Google Scholar]
  6. Casten, U.1984. Subsurface gravity measurements to demonstrate mining‐induced changes in rock density. Geophysikai Kozlemenyek30, 227–236.
    [Google Scholar]
  7. Casten, U. and Fajklewicz, Z.1986. Die Überwachung gebirgsschlaggefährdeter Bereiche mit der Mikrogravimetrie, Glückauf-Forsch.H.47, 290–295.
    [Google Scholar]
  8. Casten, U. and Fajklewicz, Z.1989. Kontrolle bergmännischer Entspannungsmassnahmen mit der Mikrogravimetrie. Erdöl und Kohle-Erdgas-Petrochemie/Hydrocarbon Technology42, 273–277.
    [Google Scholar]
  9. Casten, U. and Gram, Chr.1989. Recent developments in underground gravity surveys. Geophysical Prospecting37, 73–90.
    [Google Scholar]
  10. Fajklewicz, Z.1976. The application of microgravimetry in coal mining. Publications of the Institute of Geophysics, Polish Academy of SciencesM‐1(97), 223–234 (in Polish).
    [Google Scholar]
  11. Fajklewicz, Z.1979. Versuch zur Voraussage von Gebirgsschlägen bei Anwendung der mikrogravimetrischen Methode. IV. Internationales Symposium für Markscheidewesen, Eurogress Aachen, Band3, 237–247.
    [Google Scholar]
  12. Fajklewicz, Z.1983. Rock burst forecasting and genetic research in coal mines by microgravity method. Geophysical Prospecting31, 748–765.
    [Google Scholar]
  13. Fajklewicz, Z.1986. Origin of the anomalies of gravity and its vertical gradient over cavities in brittle rock. Geophysical Prospecting34, 1233–1254.
    [Google Scholar]
  14. Fajklewicz, Z.1989. Microgravimetric prediction for mine tremors and destabilization process in rock mass. Advances in Coal Geophysics, R. K.Verma (ed.), 11–17. Association of Exploration Geophysicists, Hyderabad , India .
    [Google Scholar]
  15. Fajklewicz, Z., Glinski, A. and Sliz, J.1982. Some application of the underground tower gravity vertical gradient. Geophysics47, 1688–1692.
    [Google Scholar]
  16. Fajklewicz, Z. and Jakiel, K.1989. Induced gravity anomalies and seismic energy as a basis for prediction of mining tremors. Pageoph129, 535–552.
    [Google Scholar]
  17. Fajklewicz, Z. and Madej, M.1982. Beitrag zur insitu Untersuchung des Spannungswellenfeldes mittels der mikrogravimetrischen Methode. Archiwum Gornictwa27, 153–169 (in Polish with German summary).
    [Google Scholar]
  18. Golizdra, G.J.1963. The distribution of gravity field singular points for two‐dimensional bodies of certain type. Izviestia Akademii Nauk SSSR – seria Geofiziczeskaja11, 16–21 (in Russian).
    [Google Scholar]
  19. Götze, H.‐J. and Lahmeyer, B.1988. Application of three‐dimensional interactive modelling in gravity and magnetics, Geophysics53, 1096–1108.
    [Google Scholar]
  20. Hussain, A., Walach, G. and Weber, F.1981. Underground gravity survey in alpine regions. Geophysical Prospecting29, 407–425.
    [Google Scholar]
  21. Lindner, H., Hanemann, K.D. and Schubert, H.1981. Methodik zur Bestimmung der Streckenreduktion in der Untertagegravimetrie. Neue Bergbautechnik11/5, 271–276.
    [Google Scholar]
  22. Mjachkin, V.I., Brace, W.F., Sobolew, G.A. and Dietrich, J.H.1975. Two models for earthquake forerunners. Pageoph113, 169–181.
    [Google Scholar]
  23. Nabighian, M.N.1972. The analytic signal of two‐dimensional magnetic bodies with polygonal cross‐section: its properties and use for automated anomaly interpretation. Geophysics37, 507–517.
    [Google Scholar]
  24. Nabighian, M.N.1974. Additional comments on the analytic signal of two‐dimensional magnetic bodies with polygonal cross‐section. Geophysics39, 85–92.
    [Google Scholar]
  25. Pavlova, N.N.1973. Theoretical investigations of the process of the genesis of fractures in the rock mass in the conditions of volumetric strain. In The Significance of Physical and Mechanical Properties of the Rock Mass in the Location of Endogenic Beds. Science, Moscow, 74–83 (in Russian).
  26. Strakhov, V.N., Grigorieva, O.M. and Lapina, M.J.1977. The determination of singular points of two‐dimensional potential fields. Prikladnaja Geofizika85, 96–113 (in Russian).
    [Google Scholar]
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