Analysis of mining deformations based on PSInSAR technique case study of the Walbrzych coal mines (Poland)

Transcription

1 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 September 2016, Brisbane, Australia

2 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, September 2016, Brisbane, Australia 2

3 Location Fig. Boundaries of former mining grounds and extent of mined coal panels 3

4 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, September 2016, Brisbane, Australia 4

5 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

6 Mining subsidence studies in the area Fig. Subsidence predicted for the entire period of coal mining (after A. Kowalski et al.) 6

7 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, September 2016, Brisbane, Australia 7

8 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, September 2016, Brisbane, Australia 8

9 Materials and methodology Fig. Permanent Scatterer InSAR technologies, (source XVI International Mine Surveying Congress, September 2016, Brisbane, Australia 9

10 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 XVI International Mine Surveying Congress, September 2016, Brisbane, Australia 10

11 Materials and methodology Track #229 Track #458 SAR No. Date Perpendicular baseline (m) Temporal baseline (days) 1 20-Nov Mar Jul Aug Oct Dec Jan Jul Aug Oct Dec May-2005 (master scene) Jul Jun Feb Apr Sep Nov Apr Jun Dec Mar Jul Sep SAR No. Date Perpendicular baseline (m) Temporal baseline (days) 1 01-Nov Dec Jul Sep Mar Jun Jul-2004 (master scene) Aug Oct Nov Nov Sep Oct Jun Aug Oct Nov Dec Jun Oct Dec XVI International Mine Surveying Congress, September 2016, Brisbane, Australia 11

12 Materials and methodology Fig. Field and aerial photos of selected, representative PS point (source of aerial images 12

13 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, September 2016, Brisbane, Australia 13

14 Results and discussion Track #229 Track #458 Number of PS points Number of PS points with significant subsidence 621 Number of PS points with significant elevation 2926 Number of PS points Number of PS points with significant subsidence 638 Number of PS points with significant elevation 2484 XVI International Mine Surveying Congress, September 2016, Brisbane, Australia 14

15 Results and discussion 15

16 Results and discussion Track #229 16

17 Results and discussion Track #458 17

18 Conclusions First study of surface movements in the former Wałbrzych Coal Basin based on satellite interferometry, Significant surface movements in the post-mining period ( ) 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, September 2016, Brisbane, Australia 18

19 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, September 2016, Brisbane, Australia 19

20 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 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, Wroclaw, Poland