Volumetric measurement of rock movement using photogrammetry

Abstract

NIOSH ground control safety research program at Spokane, Washington, is exploring applications of photogrammetry to rock mass and support monitoring. This paper describes two ways photogrammetric techniques are being used. First, photogrammetric data of laboratory testing is being used to correlate energy input and support deformation. This information can be used to infer remaining support toughness after ground deformation events. This technique is also demonstrated in a field application. Second, field photogrammetric data is compared to crackmeter data from a deep underground mine. Accuracies were found to average 8 mm, but have produced results within 0.2 mm of true displacement, as measured by crackmeters. Application of these techniques consists of monitoring overall fault activity by monitoring multiple points around the crackmeter. A case study is provided in which a crackmeter is clearly shown to have provided insufficient information regarding overall fault ground deformation. Photogrammetry is proving to be a useful ground monitoring tool due to its unobtrusiveness and ease of use.

Photogrammetry in underground mining ground control — Lucky Friday mine case study

“…Global displacements were initially tracked using coordinates of easting, northing, and elevation (x, y, and z, respectively). To more fully understand the ground movement in relation to the F3 and F4 faults, the global x, y, and z displacements were transformed into local coordinate displacements oriented on the thrust, strike, and dilation of the fault (Benton et al 2016). Fault thrust served as the new x-axis (x"), fault strike served as the new y-axis (y"), and fault dilation -movement perpendicular to the thrust and strike of the fault -served as the new z-axis (z").…”

Quasi-static and mechanical shock testing of reinforced shotcrete surface support

“…A laboratory photogrammetry system (Benton et al 2015b) is used to measure the geometric changes of the panels, including volume changes and panel cracking. These measurements can be correlated with the load and displacement data allowing visual observation to be related to the applied force and displacement.…”

“…These measurements can be correlated with the load and displacement data allowing visual observation to be related to the applied force and displacement. The photogrammetric analysis techniques used to perform these calculations are described in detail by Benton et al (2015aBenton et al ( , 2015b. Further detail on the HEHD panel testing machine and photogrammetric methods is available in previous publications (Martin et al 2015;Raffaldi et al 2016).…”

Digital Drill Core Models: Structure-from-Motion as a Tool for the Characterisation, Orientation, and Digital Archiving of Drill Core Samples

“…The adaptation of photogrammetry in the geosciences to study the sub-metre scale has generally been slow, although the technique is widely used in outcrop-scale digitisations during stratigraphic, structural, and sedimentological characterisations (e.g., [17][18][19][20]). In geotechnics, SfM is increasingly being used to determine in situ stresses during deformation tests through changes in local volumes and fracture mapping [21][22][23][24][25]. Although the potential of digital rock models has been outlined (e.g., [26]), current geoscientific workflows fall short of the full and complete digitisation of samples as, for example, applied in palaeontology (e.g., [27]).…”