Simulating the Interaction between Groundwater and Brittle Failure in Open Pit Slopes
This paper presents the results of a study on the
influence of varying percentages of rock bridges along a basal surface
defining a biplanar failure mode. A pseudo-coupled-hydromechanical
brittle fracture analysis is adopted using the state-of-the-art code
Slope Model. Model results show that rock bridge failure is strongly
influenced by the incorporation of groundwater pressures. The
models show that groundwater pressure can promote total failure of a
5% rock bridge along the basal surface. Once the percentage of the
rock bridges increases to 10 and 15%, although, the rock bridges are
broken, full interconnection of the surface defining the basal surface
of the biplanar mode does not occur. Increased damage is caused
when the rock bridge is located at the daylighting end of the basal
surface in proximity to the blast damage zone. As expected, some
cracking damage is experienced in the blast damage zone, where
properties representing a good quality controlled damage blast
technique were assumed. Model results indicate the potential increase
of permeability towards the blast damage zone.
[1] Read, J., Beale, G., 2014. Guidelines for Evaluating Water in Pit Slope
Stability. CSIRO Publishing. Collingwood, Victoria, 510pp.
[2] Vivas, J. Groundwater Characterization and Modelling in Natural and
Open Pit Rock Slopes. (M.Sc. Thesis), Simon Fraser University.
Burnaby, BC, Canada.
[3] Sullivan, T. D., 2007. Hydromechanical coupling and pit slope
movements." In: Slope Stability Proceedings of the International
Symposium on Rock Stability in Open Pit Mining.
[4] Read, J., Stacey, P., 2009. Guidelines for Open Pit Slope Design. CSIRO
Publishing. Collingwood, Victoria, 512pp.
[5] Taseko, 2012. Preliminary Pit Slope Design (No. VA101-266/27-1).
Taseko Mines Limited Consulting, Vancouver, Canadá, 78 pp.
[6] Hoek, E., 2002a. Blasting damage in rock, RocScience, 8 pp. Available
online: https://www.rocscience.com/hoek/references/H2002.pdf
[7] Robertson, A.M., 1970. The interpretation of geological factors for use
in slope theory. Planning Open, in: Planning Open Pit Mines,
Proceedings. Johannesburg, pp. 55–71.
[8] Diederichs, M.S., Kaiser, P.K., 1999. Tensile strength and abutment
relaxation as failure control mechanisms in underground excavations.
Int. J. Rock Mech. Min. Sci. Vol. 36, pp. 69–96. doi:10.1016/S0148-
9062(98)00179-X.
[9] Saiang, D., Nordlund, E., 2008. Numerical study of the mechanical
behaviour of the damaged rock mass around an underground excavation,
in: 5th International Conference and Exhibition on Mass Mining.
Presented at the International Conference & Exhibition on Mass Mining,
Lulea, Sweden, pp. 803–813.
[10] Coates, D. F. and Brown, A., 1961. “Stability of slopes at mines”, The
Canadian Mining and Metallurgical Bulletin.
[11] Beale, G., Read, J., 2014. Guidelines for Evaluating Water in Pit Slope
Stability. CRC Press, Australia.616 pp.
[12] Havaej, M., Stead, D., Lorig, L., Vivas, J., 2012. Modelling rock bridge
failure and brittle fracturing in large open pit rock slopes, in: ARMA
2012. Presented at the 46th US Rock Mechanics / Geomechanics
Symposium held in Chicago, IL, USA,, American Rock Mechanics
Association, Chicago, IL, USA. 9 pp.
[13] Havaej, M., Wolter, A., Stead, D., Tuckey, Z., Lorig, L., Eberhardt, E.,
2013.Incorporating brittle fracture into three-dimensional modelling of
rock slopes. In: Proceedings of the 2013 International Symposium on
Slope Stability in Open Pit. Mining and Civil Engineering, Brisbane,
Australia., pp. 625–638.
[14] Jennings J. E. (1970). A mathematical theory for the calculation of the
stability of open cast mines. In Van Rensburg, P. (Eds.), Planning open
pit mines: Proceedings of the Symposium on the Theoretical
Background to the Planning of Open Pit Mines with Special Reference
to Slope Stability (pp. 87-102). Johannesburg, Republic of South Africa:
Balkema (A.A.)
[15] Tuckey, Z., 2012. An Integrated Field Mapping-Numerical Modelling
Approach to Characterising Discontinuity Persistence and Intact Rock
Bridges in Large Open Pit Slopes (M.Sc. Thesis). Simon Fraser
University. Burnaby, BC, Canada.
[16] Itasca Consulting Group, Inc., 2014. Slope Model Manual. Minneapolis,
USA.
[17] Lorig LJ, Cundall PA, Damjanac B, Emam S. A three-dimensional
model for rock slopes based on micromechanics. In: Proceedings of the
44th US Rock Mech Symp 5th US-Can Rock Mech Symp; 2010.
[18] Hoek, E., 2012. Blast Damage Factor D. In: Technical note for
RocNews, February 2, 2012, Winter 2012 Issue, RocScience, pp. 6-8.
Available from: www.rocscience.com/assets/files/uploadss/8584.pdf
[19] Zhang, L., 2013. Aspects of rock permeability. Frontiers of Structural
and Civil Engineering. Vol. 7, pp. 102–116. doi:10.1007/s11709-013-
0201-2.
[1] Read, J., Beale, G., 2014. Guidelines for Evaluating Water in Pit Slope
Stability. CSIRO Publishing. Collingwood, Victoria, 510pp.
[2] Vivas, J. Groundwater Characterization and Modelling in Natural and
Open Pit Rock Slopes. (M.Sc. Thesis), Simon Fraser University.
Burnaby, BC, Canada.
[3] Sullivan, T. D., 2007. Hydromechanical coupling and pit slope
movements." In: Slope Stability Proceedings of the International
Symposium on Rock Stability in Open Pit Mining.
[4] Read, J., Stacey, P., 2009. Guidelines for Open Pit Slope Design. CSIRO
Publishing. Collingwood, Victoria, 512pp.
[5] Taseko, 2012. Preliminary Pit Slope Design (No. VA101-266/27-1).
Taseko Mines Limited Consulting, Vancouver, Canadá, 78 pp.
[6] Hoek, E., 2002a. Blasting damage in rock, RocScience, 8 pp. Available
online: https://www.rocscience.com/hoek/references/H2002.pdf
[7] Robertson, A.M., 1970. The interpretation of geological factors for use
in slope theory. Planning Open, in: Planning Open Pit Mines,
Proceedings. Johannesburg, pp. 55–71.
[8] Diederichs, M.S., Kaiser, P.K., 1999. Tensile strength and abutment
relaxation as failure control mechanisms in underground excavations.
Int. J. Rock Mech. Min. Sci. Vol. 36, pp. 69–96. doi:10.1016/S0148-
9062(98)00179-X.
[9] Saiang, D., Nordlund, E., 2008. Numerical study of the mechanical
behaviour of the damaged rock mass around an underground excavation,
in: 5th International Conference and Exhibition on Mass Mining.
Presented at the International Conference & Exhibition on Mass Mining,
Lulea, Sweden, pp. 803–813.
[10] Coates, D. F. and Brown, A., 1961. “Stability of slopes at mines”, The
Canadian Mining and Metallurgical Bulletin.
[11] Beale, G., Read, J., 2014. Guidelines for Evaluating Water in Pit Slope
Stability. CRC Press, Australia.616 pp.
[12] Havaej, M., Stead, D., Lorig, L., Vivas, J., 2012. Modelling rock bridge
failure and brittle fracturing in large open pit rock slopes, in: ARMA
2012. Presented at the 46th US Rock Mechanics / Geomechanics
Symposium held in Chicago, IL, USA,, American Rock Mechanics
Association, Chicago, IL, USA. 9 pp.
[13] Havaej, M., Wolter, A., Stead, D., Tuckey, Z., Lorig, L., Eberhardt, E.,
2013.Incorporating brittle fracture into three-dimensional modelling of
rock slopes. In: Proceedings of the 2013 International Symposium on
Slope Stability in Open Pit. Mining and Civil Engineering, Brisbane,
Australia., pp. 625–638.
[14] Jennings J. E. (1970). A mathematical theory for the calculation of the
stability of open cast mines. In Van Rensburg, P. (Eds.), Planning open
pit mines: Proceedings of the Symposium on the Theoretical
Background to the Planning of Open Pit Mines with Special Reference
to Slope Stability (pp. 87-102). Johannesburg, Republic of South Africa:
Balkema (A.A.)
[15] Tuckey, Z., 2012. An Integrated Field Mapping-Numerical Modelling
Approach to Characterising Discontinuity Persistence and Intact Rock
Bridges in Large Open Pit Slopes (M.Sc. Thesis). Simon Fraser
University. Burnaby, BC, Canada.
[16] Itasca Consulting Group, Inc., 2014. Slope Model Manual. Minneapolis,
USA.
[17] Lorig LJ, Cundall PA, Damjanac B, Emam S. A three-dimensional
model for rock slopes based on micromechanics. In: Proceedings of the
44th US Rock Mech Symp 5th US-Can Rock Mech Symp; 2010.
[18] Hoek, E., 2012. Blast Damage Factor D. In: Technical note for
RocNews, February 2, 2012, Winter 2012 Issue, RocScience, pp. 6-8.
Available from: www.rocscience.com/assets/files/uploadss/8584.pdf
[19] Zhang, L., 2013. Aspects of rock permeability. Frontiers of Structural
and Civil Engineering. Vol. 7, pp. 102–116. doi:10.1007/s11709-013-
0201-2.
@article{"International Journal of Earth, Energy and Environmental Sciences:71595", author = "Janisse Vivas and Doug Stead and Davide Elmo and Charles Hunt", title = "Simulating the Interaction between Groundwater and Brittle Failure in Open Pit Slopes", abstract = "This paper presents the results of a study on the
influence of varying percentages of rock bridges along a basal surface
defining a biplanar failure mode. A pseudo-coupled-hydromechanical
brittle fracture analysis is adopted using the state-of-the-art code
Slope Model. Model results show that rock bridge failure is strongly
influenced by the incorporation of groundwater pressures. The
models show that groundwater pressure can promote total failure of a
5% rock bridge along the basal surface. Once the percentage of the
rock bridges increases to 10 and 15%, although, the rock bridges are
broken, full interconnection of the surface defining the basal surface
of the biplanar mode does not occur. Increased damage is caused
when the rock bridge is located at the daylighting end of the basal
surface in proximity to the blast damage zone. As expected, some
cracking damage is experienced in the blast damage zone, where
properties representing a good quality controlled damage blast
technique were assumed. Model results indicate the potential increase
of permeability towards the blast damage zone.", keywords = "Slope model, lattice spring, blasting damage zone.", volume = "9", number = "12", pages = "1344-9", }
