A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Geostatistical modeling of Rock Quality Designation (RQD) and geotechnical zoning accounting for directional dependence and scale effect
Abstract The characterization of rock masses is an essential component for the planning and development of engineering designs in rock mechanics and rock engineering. The Rock Quality Designation (RQD) is a widely used rock mass characterization system that is direction-dependent, i.e., the measurement of a core sample depends not only on the sample position but also on its orientation. This paper outlines the critical aspects of the determination of RQD and proposes a physically-based upscaling strategy from borehole samples to large blocks, based on block-averaging the RQD values corresponding to the same direction, then calculating the minimum value over all the directions. An anisotropy index indicating how much RQD varies between one direction and another is also derived. Using geostatistical simulation, our proposal allows interpolating and upscaling direction-dependent geotechnical variables like RQD at any place in the geographical space for any direction, avoiding directional biases. We illustrate this proposal by predicting RQD in a polymetallic deposit, achieving geotechnical zoning and comparing the results with those of the traditional approach where the directional dependence of RQD is ignored.
Highlights Rock Quality Designation (RQD) depends on core sample location and direction. Upscaling should not mix RQD values measured along different directions. Direction-dependent variables can be regionalized in a 3D space cross a 2D sphere. Geostatistical simulation interpolates RQD at any target location and direction. Upscaling based on block-averaging RQD along the same direction is proposed.
Geostatistical modeling of Rock Quality Designation (RQD) and geotechnical zoning accounting for directional dependence and scale effect
Abstract The characterization of rock masses is an essential component for the planning and development of engineering designs in rock mechanics and rock engineering. The Rock Quality Designation (RQD) is a widely used rock mass characterization system that is direction-dependent, i.e., the measurement of a core sample depends not only on the sample position but also on its orientation. This paper outlines the critical aspects of the determination of RQD and proposes a physically-based upscaling strategy from borehole samples to large blocks, based on block-averaging the RQD values corresponding to the same direction, then calculating the minimum value over all the directions. An anisotropy index indicating how much RQD varies between one direction and another is also derived. Using geostatistical simulation, our proposal allows interpolating and upscaling direction-dependent geotechnical variables like RQD at any place in the geographical space for any direction, avoiding directional biases. We illustrate this proposal by predicting RQD in a polymetallic deposit, achieving geotechnical zoning and comparing the results with those of the traditional approach where the directional dependence of RQD is ignored.
Highlights Rock Quality Designation (RQD) depends on core sample location and direction. Upscaling should not mix RQD values measured along different directions. Direction-dependent variables can be regionalized in a 3D space cross a 2D sphere. Geostatistical simulation interpolates RQD at any target location and direction. Upscaling based on block-averaging RQD along the same direction is proposed.
Geostatistical modeling of Rock Quality Designation (RQD) and geotechnical zoning accounting for directional dependence and scale effect
Sánchez, L. Katherine (author) / Emery, Xavier (author) / Séguret, Serge A. (author)
Engineering Geology ; 293
2021-08-17
Article (Journal)
Electronic Resource
English
Geotechnical zoning of crystalline rock mass
| British Library Conference Proceedings | 1994
Probabilistic simulation of rock quality designation (RQD)
| Online Contents | 1991
Study on the conditions and problems of zoning area designation
| British Library Online Contents | 2014