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Remote sensing techniques in underground mining: Application of terrestrial LIDAR for
stability analysis and optimization of excavation activities
Vanneschi C., Coggan J., Mastrorocco G., Francioni M., Eyre M., Salvini R.
A detailed knowledge of the structural setting of a rock mass is essential for proper planning of safe
underground excavation activities. Terrestrial LiDAR technology can allow detailed remote data
acquisition not only for determination of mine rock face geometry but also for evaluation of the
spatial characteristics of discontinuities. This remote data collection can be combined with traditional
engineering-geological surveys for deterministic mapping of the discontinuity sets to be used in
subsequent stability analysis (Francioni et. al, 2014). In addition, tunnel excavation changes the preexisting stress state, which can induce brittle deformations that may lead to instability in the
excavation walls and a reduction of the quality of the extracted material. It is therefore very important
to consider changes over time in stress orientation and stress magnitude in the mining area; these are
influenced by both new tunnel excavations and by the presence of discontinuities, especially within a
competent marble rock mass.
This case study provides an example of a working approach that combines terrestrial LiDAR and
traditional geological surveys for engineering-geological investigations. A three-dimensional model
(Vanneschi et al., 2014), which includes information about the geological structures in an
underground marble mine in the Apuan Alps, is combined with information about discontinuities
identified and mapped in a deterministic way by using the LeicaTM TruView plug-in, which manages
laser scanning data plus high definition images and allows georeferenced representation of the
fractures. After GIS processing and additional in situ engineering-geological surveys, data was used to
create a 3D virtual reality illustrating the deterministic fracture pattern and properties of the single
discontinuities. The detailed documentation of the geomechanical and geostructural characteristics of
the discontinuities was subsequently used to perform numerical modelling analyses, to provide further
insight into likely stress conditions. The results of the investigation can be used to improve
optimization of the excavation activities, taking in consideration the effects of local variation of the
stress which is primarily reflected in situ by observed fracturing.
References
Francioni M., Salvini R., Stead D. & Litrico S. 2014. A case study integrating remote sensing and
distinct element analysis to quarry slope stability assessment in the Monte Altissimo area, Italy. Eng.
Geol., 183, 290-302.
Vanneschi C., Salvini R., Massa G., Riccucci S. & Borsani A. 2014. Geological 3D modeling for
excavation activity in an underground marble quarry in the Apuan Alps (Italy). Comput. Geosci., 69,
41-54.
Key-words
Terrestrial LiDAR, underground mining, stability analysis, marble, numerical modelling