NF XP P94-424 standard shear test for estimating the mechanical properties of rock joints sampled from Yaounde gneisses (Cameroon)

Authors

  • Roger Bissaya Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon
  • Aurélie Kamwa Ngamy Department of Mining Engineering and Treatment of Minerals, University of Maroua, Postal address: Box 46, Maroua, Cameroon
  • Robert Eko Medjo Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon
  • Richard Tanwi Ghogomu Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon; Department of Industrial Security, Quality and Environment, University of Maroua, Postal address: Box 46, Maroua, Cameroonameroon)
  • Bernard Njom Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon

DOI:

https://doi.org/10.38208/jgg.v1i1.312

Keywords:

joint, rock mechanics, shear test, friction angle, Yaounde, Cameroon

Abstract

This study is a contribution to the knowledge of rocks mechanical properties in Yaounde, with a scope on failure parameters. In most instances, this goal is achieved by carrying out XP P94-424 standard shear tests. Thus, the tests were carried out on two joint samples, using the experimental device of the Fondasol laboratory (France). However, the pairs of shear – normal stress values were plotted or computed to determine other relevant parameters. The results are expressed as graphs and value reports. (1) The global friction angle ranges around 36° for unsmoothed joints, and decreases up to 34° for smoothed joints. The friction angle ranges around 49° - 46° for unsmoothed joints, and decreases up to 3.90° for smoothed joints. The dilatancy i depend on the roughness and the type of joint surfaces; e. g. it ranged around 7° for the roughest surface while it ranged around 4° on the other. (2) At the peak the cohesion ranges around 81 kPa however, the wetness might affect this parameter up to its nullifying.  At residual the cohesion ranges around 91 – 135 kPa.

Author Biographies

Aurélie Kamwa Ngamy, Department of Mining Engineering and Treatment of Minerals, University of Maroua, Postal address: Box 46, Maroua, Cameroon

Department of Mining Engineering and Treatment of Minerals

Robert Eko Medjo, Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon

Department of Earth Sciences, University of Yaounde 1

Richard Tanwi Ghogomu, Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon; Department of Industrial Security, Quality and Environment, University of Maroua, Postal address: Box 46, Maroua, Cameroonameroon)

Department of Earth Sciences, University of Yaounde 1,

3    Department of Industrial Security, Quality and Environment

Bernard Njom, Department of Earth Sciences, University of Yaounde 1, Faculty of Science, Postal address: Box 812, Yaounde, Cameroon

Department of Earth Sciences, University of Yaounde 1

Published

2022-11-08

How to Cite

Bissaya, R., Ngamy, A. K., Medjo, R. E., Ghogomu, R. T., & Njom, B. (2022). NF XP P94-424 standard shear test for estimating the mechanical properties of rock joints sampled from Yaounde gneisses (Cameroon). Journal of Geomechanics and Geoengineering, 1, 39-50. https://doi.org/10.38208/jgg.v1i1.312

Issue

Vol. 1 (2023): JGG: Volume 1

Section

Articles

Copyright (c) 2022 Roger Bissaya, Aurélie Kamwa Ngamy , Robert Eko Medjo , Richard Tanwi Ghogomu , Bernard Njom

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