Analysis of mining deformations based on PSInSAR technique case study of the Walbrzych coal mines (Poland) Dr. Jan Blachowski, Dr. Wojciech Milczarek Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, Poland XVI International Mine Surveying Congress 12-16 September 2016, Brisbane, Australia
Introduction (plan of presentation) Location and history of subsidence studies in the Wałbrzych Coal Basin Materials and methodology Results and discussion Conclusions (further work) XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 2
Location Fig. Boundaries of former mining grounds and extent of mined coal panels 3
ROOF COLLAPSE Geological and mining settings Fig. Representative geological cross-section Fig. Mining systems predominatly used in the Wałbrzych coal mines, longwall with roof collapse (left), longwall with dry fill (right) (after Kowalski, 2000) XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 4
Hydrogeological and mining settings (1999) (2005) (1997) Note: In brackets year of groundwater table restoration Fig. Approximate extent of underground water reserviors (after J. Fiszer) 5
Mining subsidence studies in the area Fig. Subsidence predicted for the entire period of coal mining (after A. Kowalski et al.) 6
Mining subsidence studies in the area Fig. Map of vertical movements between 1972 and 1993 Fig. Map of vertical movements between 1993 and 2014 XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 7
Introduction (plan of presentation) Location and history of subsidence studies in the Wałbrzych Coal Basin Materials and methodology Results and discussion Conclusions (further work) XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 8
Materials and methodology Fig. Permanent Scatterer InSAR technologies, (source http://tre-altamira.com/technology) XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 9
Materials and methodology Data ESA Envisat, 24 scenes from track 229, 21 scenes from track 458, DTM (SRTM) Software Doris, STAMPS/MTI, Matlab. 458 track master scene 23 July 2004, 229 track master scene 18 May 2005. XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 10
Materials and methodology Track #229 Track #458 SAR No. Date Perpendicular baseline (m) Temporal baseline (days) 1 20-Nov-2002-163 -910 2 05-Mar-2003 100-805 3 23-Jul-2003-321 -695 4 27-Aug-2003-158 -630 5 01-Oct-2003 933-595 6 10-Dec-2003 344-525 7 14-Jan-2004 508-490 8 07-Jul-2004 408-345 9 11-Aug-2004 572-280 10 20-Oct-2004-832 -210 11 29-Dec-2004 867-140 12 18-May-2005 (master scene) 0 0 13 27-Jul-2005 324 40 14 07-Jun-2006 210 415 15 07-Feb-2007-178 630 16 18-Apr-2007-230 700 17 05-Sep-2007 583 840 18 14-Nov-2007 437 910 19 02-Apr-2008 439 1050 20 11-Jun-2008 135 1120 21 23-Dec-2009-246 1680 22 03-Mar-2010 153 1750 23 21-Jul-2010-202 1860 24 29-Sep-2010 782 1960 SAR No. Date Perpendicular baseline (m) Temporal baseline (days) 1 01-Nov-2002-214 -630 2 06-Dec-2002-223 -595 3 04-Jul-2003-221 -385 4 12-Sep-2003-53 -315 5 05-Mar-2004 62-140 6 18-Jun-2004-101 -35 7 23-Jul-2004 (master scene) 0 0 8 27-Aug-2004 445 35 9 21-Oct-2005-265 455 10 25-Nov-2005 486 490 11 10-Nov-2006 589 840 12 21-Sep-2007 705 1155 13 26-Oct-2007 224 1190 14 27-Jun-2008 156 1435 15 01-Aug-2008 131 1470 16 10-Oct-2008-112 1540 17 14-Nov-2008 523 1575 18 19-Dec-2008-26 1610 19 12-Jun-2009-42 1785 20 30-Oct-2009-28 1925 21 04-Dec-2009 606 1960 XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 11
Materials and methodology Fig. Field and aerial photos of selected, representative PS point (source of aerial images http://geoportal.dolnyslask.pl) 12
Introduction (plan of presentation) Location and history of subsidence studies in the Wałbrzych Coal Basin Materials and methodology Results and discussion Conclusions (further work) XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 13
Results and discussion Track #229 Track #458 Number of PS points 8 201 Number of PS points with significant subsidence 621 Number of PS points with significant elevation 2926 Number of PS points 10 447 Number of PS points with significant subsidence 638 Number of PS points with significant elevation 2484 XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 14
Results and discussion 15
Results and discussion Track #229 16
Results and discussion Track #458 17
Conclusions First study of surface movements in the former Wałbrzych Coal Basin based on satellite interferometry, Significant surface movements in the post-mining period (2002-2010) registered with PSInSAR technique, Rate of elevation of PS points up to 6 mm/yr, Steady elevation for the central zone, Elevation diminishing in time and stabilisation for the two other zones, XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 18
Conclusions Probably observed delayed response of rock mass to restoration of original ground water table after end of mine water drainage, Further studies underway aimed at analysis of surface changes in the period of groundwater table restoration and utilising SBAS technique XVI International Mine Surveying Congress, 12-16 September 2016, Brisbane, Australia 19
Acknowledgments Polish National Science Centre Project Development of a numerical method of mining ground deformation modelling in complex geological and mining conditions UMO-2012/07/B/ST10/04297 EU ESA Project no. 18310 Identification of rock mass surface deformations on abandoned mining areas Thank you for you attention Further information Jan Blachowski, Wojciech Milczarek jan.blachowski@pwr.edu.pl, wojciech.milczarek@pwr.edu.pl Geodesy and Geoinformatics Division Faculty of Geoengineering, Mining and Geology Wroclaw University of Science and Technology ul. Na Grobli 15, 50-421 Wroclaw, Poland