Passive seismic velocity tomography on longwall mining panel based on simultaneous iterative reconstructive technique (SIRT)

Abstract

Mining operation, especially underground coal mining, always has the remarkable risks of ground control. Passive seismic velocity tomography based on simultaneous iterative reconstructive technique (SIRT) inversion is used to deduce the stress redistribution around the longwall mining panel. The mining-induced microseismic events were recorded by mounting an array of receivers on the surface, above the active panel. After processing and filtering the seismic data, the three-dimensional tomography images of the p-wave velocity variations by SIRT passive seismic velocity tomography were provided. To display the velocity changes on coal seam level and subsequently to infer the stress redistribution, these three-dimensional tomograms into the coal seam level were sliced. In addition, the boundary element method (BEM) was used to simulate the stress redistribution. The results show that the inferred stresses from the passive seismic tomograms are conformed to numerical models and theoretical concept of the stress redistribution around the longwall panel. In velocity tomograms, the main zones of the stress redistribution around the panel, including front and side abutment pressures, and gob stress are obvious and also the movement of stress zones along the face advancement is evident. Moreover, the effect of the advance rate of the face on the stress redistribution is demonstrated in tomography images. The research result proves that the SIRT passive seismic velocity tomography has an ultimate potential for monitoring the changes of stress redistribution around the longwall mining panel continuously and subsequently to improve safety of mining operations.

Keywords

longwall mining / passive seismic velocity tomography / simultaneous iterative reconstructive technique (SIRT) / boundary element method / stress redistribution / ground control

References

[1] PengS. S.Coal mine ground control [M], 20083rd edEnglewood, USASociety for Mining, Metallurgy, and Exploration, Inc. (SME)

[2] PengS. S.Longwall mining [M], 20062nd ed.Englewood, USASociety for Mining, Metallurgy, and Exploration, Inc. (SME)

[3] JeremicM. L.Strata mechanics in coal mining [M], 1985Rotterdam, NetherlandsA. A. BALKEMA

[4] YoungR. P., MaxwellS. C.. Seismic characterization of a highly stressed rock mass using tomographic imaging and induced seismicity [J]. Journal of Geophysical Research, 1992, 97(B9): 12361-12373

[5] BradyB. H. G., BrownE. T.Rock mechanics for underground mining [M], 2004LondonGeorge Allen & Unwin

[6] CoxM.Static corrections for seismic reflection surveys [M], 1999TulsaSociety of Exploration Geophysicists

[7] LeeW. H. K., PereyraV.Mathematical introduction to seismic tomography, inseismic tomography: Theory and practice [M], 1993LondonChapman and Hall9-22

[8] SWANSON P, ESTEY L, BOLER F, BILLINGTON S. Accuracy and precision of microseismic event locations in rock burst research studies [R]. Report of investigations (U.S. Bureau of Mines) No. 9395, NIOSH, 1992.

[9] LuxbacherK., WestmanE., SwansonP., KarfakisM.. Three-dimensional time-lapse velocity tomography of an underground longwall panel [J]. International Journal of Rock Mechanics and Mining Sciences, 2008, 45(4): 478-485

[10] MenkeW.Geophysical data analysis: Discrete inverse theory [M], 19892nd edSan DiegoInternational Geophysics Series, Harcourt Brace Jovanovich

[11] TarantolaA.Inverse problem theory: Methods for data fitting and model parameter estimation [M], 1987AmsterdamElsevier

[12] SantamarinaJ. C., FrattaD.Discrete signals and inverse problem: An introduction for engineers and scientists [M], 2005New YorkWiley

[13] SoldatiG., BoshiL.. The resolution of whole earth seismic tomographic models [J]. Geophysical Journal International, 2005, 161(1): 143-153

[14] WatanabeT., MatsuokaT., AshidaY.. Seismic travel-time tomography using fresnel volume approach [C]. Proceedings of the 69th SEG Annual Meeting, 1999HoustonSEG1402-1405

[15] TselentisG. A., SerpetsidakiA., MartakisN., SokosE., ParaskevopoulosP., KapotasS.. Local high-resolution passive seismic tomography and kohonen neural networks-Application at the rio-antirio strait, central greece [J]. Geophysics Journal, 2007, 72(4): 93-106

[16] MSHA. Data retrieval system [EB/OL]. http://www.msha.gov/drs/drshome.htm. [2007-24-10]. 2010.

[17] LuxbacherK., WestmanE., SwansonP.. Time-lapse tomography of a longwall panel: A comparison of location schemes [C]. Proceedings of the 26th International Conference on Ground Control in Mining, 2008Morgantown, West Virginia UniversityICGCM217-225

[18] NoletG.A breviary of seismic tomography [M], 2008UKCambridge University Press

[19] BobetA.. Numerical methods in geomechanics [J]. The Arabian Journal for Science and Engineering, 2010, 35(1B): 27-48

[20] NIOSH. LAMODEL software-stress and displacement calculations [EB/OL]. [2003-03-09]. http://origin.cdc.gov/niosh/mining/products/product54.htm.