Abstract SYMPHOS 2011

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CONCEPTION ET RÉALISATION DES TALUS DE MINES À CIEL OUVERT
APPROCHE GÉOLOGIQUE ET GÉOMÉCANIQUE
MN-O-01
Jean-Alain FLEURISSON
MINES ParisTech - Centre de Géosciences
Fontainebleau/FRANCE
Les talus de mine à ciel ouvert doivent être reconnus comme des ouvrages géotechniques à part entière dont
le dimensionnement, réalisé suivant les règles de l’art, doit prendre en compte des préoccupations techniques,
économiques, environnementales et de sécurité. Mais ces ouvrages sont, avant tout, des ouvrages géologiques
et géomécaniques naturels pour lesquels la structure géologique et la nature pétrographique des matériaux
constitutifs contrôlent les processus de déformation et de rupture par rapport auxquels il faut les dimensionner.
Il importe donc de mettre en œuvre une méthodologie bien maîtrisée qui peut se décomposer en plusieurs étapes :
1) la caractérisation du massif rocheux par l’acquisition, puis l’analyse de données géologiques et
géomécaniques ;
2) la détermination des mécanismes potentiels de déformation et de rupture, et leur modélisation ;
3) l’analyse des facteurs déclenchants ou aggravants des ruptures.
Cet article présente différentes techniques et outils existants pour aborder ces étapes successives, et illustre leur
mise en œuvre pratique ainsi que leurs limitations par des études de cas de dimensionnement de mines à ciel
ouvert.
SLOPE DESIGN AND IMPLEMENTATION IN OPEN PIT MINES : GEOLOGICAL AND GEOMECHANICAL APPROACH
Slopes in open pit mines must be considered as geotechnical structures. Therefore their design and implementation
must be conducted with all consideration including technical, economical, environmental and safety issues. But
these structures are above all natural geological and geomechanical features and the geological structures as well
as the petrographical nature of the rock material control the deformation and failure mechanisms.
It is therefore important to implement a well-defined methodology which should be conducted according to
the following phases: 1) rock mass characterization derived from the acquisition and analysis of geological and
geomechanical data; 2) determination of the potential mechanisms of deformation and failure, and their numerical
modelling; 3) analysis of triggering or aggravating factors of failure.
This paper presents various available techniques and tools to achieve these successive phases and illustrate their
implementation and also limitations through case studies of slope design in open pit mines.
GRIDDED SEAM VS 3D BLOCK MODELS IN MINE PLANNING
OF PHOSPHATE DEPOSITS
MN-O-02
Daniel M GAGNON
P. Eng, Manager – Mining Group – Met-Chem Canada Inc,
Montreal, QUEBEC CANADA
Advantages of using gridded seam models over 3D block models for mine planning of industrial
minerals and other tabular deposits such as phosphates.
Keywords: Gridded Seam, 3D block model, mine design, mine planning
Met-Chem Canada Inc. is an engineering consulting firm serving the mining industry since 1969 and based in
Montreal Canada. Met-Chem is a wholly owned subsidiary of UEC Technologies LLC which is part of United States
Steel Corporation. Mining engineers and geologists at Met-Chem have been using 3D block models and gridded
seam models since the mid-80s for geological modelling, resource/reserve estimation, economic evaluations and
mine planning.
Over the years, Met-Chem has prepared numerous mine plans for mining operations based on either 3D Block models
or Gridded Seam models developed by Met-Chem or client geologists. These models were initially developed by the