1. Photogrammetric Monitoring of Rock Mass Behavior in Deep Vein Mining Donovan Benton, Mining Engineer Stephen Iverson, Mining Engineer Jeffrey Johnson, Mining Engineer Lewis Martin, Research Mechanical Engineer NIOSH, Office of Mine Safety and Health Research Spokane, WA

2. Outline Field photogrammetry system Lab photogrammetry system Measurement verification Field Lab Lab verification

3. Field Photogrammetry System Three auxiliary lights Nikon D80 camera Sigma 10mm-20mm lens Tripod Survey control points

4. Simple field setup Camera spacing Distance to face Pixel density Control points or scale D D/5 to D/8 plan view

5. Photogrammetry Reconstruction Fault Trace Three pairs merged

6. Quality Improvement January 2013--camera handheld using flash May 2013--Tripod, auxiliary lights, timed exposure

7. Closer Look

8. Photogrammetry Software Shapemetrix3D—3GSM 3DM Analyst—Adam Technology PhotoModeler Scanner—Eos Systems Inc. Bundler/PMVS2—Open source software Sirovision—CAE Mining PMVS2--Patch-based Multi-view Stereo Software

9. Alternative

10. Changing Ground Conditions

11. Unity Software Visualization photogrammetric monitoring of fault exposures to fully characterize observable slip

12. Lab Photogrammetry System Camera type Nikon D800 digital SLR LensSigma 20 mm Horizontal field of view 84 degrees Vertical field of view61 degrees Effective image pixels36.3 million Pixel resolution at 5 m0.1 cm by 0.1 cm

13. High Energy High Displacement Test (HEHD)

14. Stripping Panel Forms

15. Mount and Torque Panels

16. Panel Test

17. Panel Test (1 frame per second)

18. Point Cloud Reconstruction

19. Measurement Verification

20. Accuracy Results Linear measure Volume measure

21. Absolute and Average Error

22. Measurement Verification Summary Field system Average linear error was +/- 0.03 inches. Lab system Average linear error was +/- 0.05 inches. Average volume error was +- 1.76 percent.

23. Photogrammetry Conclusions The field system is a fast and relatively inexpensive way to document site conditions. The lab system using dual cameras allows documentation for fast moving experiments. Linear and volumetric measures are within acceptable limits for determining ground movement.

24. Questions?