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IJSTR >> Volume 8 - Issue 4, April 2019 Edition



International Journal of Scientific & Technology Research  
International Journal of Scientific & Technology Research

Website: http://www.ijstr.org

ISSN 2277-8616



Slope Stability Of The Middle Stack Of An Open Pit

[Full Text]

 

AUTHOR(S)

Wang Yiming, Trevor Siame, Victor Mwango Bowa

 

KEYWORDS

Slope failure; middle stack; the factor of safety; the probability of failure; drained and undrained conditions; acceptance failure criteria.

 

ABSTRACT

Chimiwungo main open pit has experienced slope failure in the weathered rock formation in the middle stack for a decade now. In this article, the geotechnical analysis was conducted to determine the factor of safety and probability of failure of the middle stack using limit equilibrium method under both drained and undrained conditions. The factor of safety and probability of failure index were calculated as they provide the objective measure of the risk of the failure associated with a slope design. The actual stack performance was compared to various slope stability acceptance criteria with results subjected to a more thorough analysis of the consequences of failure. The study indicates that under dry to semi-drained conditions, the factor of safety and the probability of failure were compliant to all the acceptability slope stability failure criterion. This entails under dry and partially drained conditions, the middle stack of the Chimiwungo Open Pit is predicted to remain stable. As the undrained condition of the stack is above 30% of water content, the resulting safety factor and the probability of failure becomes out of compliance with the acceptance slope stability failure criterion. This entails the performance of the stack with respect to acceptance failure criteria falls below the minimum mean factor of safety and violates probability acceptance failure criteria, leading to unstable stack. The study recommends major modification to the stack geometry and that the stability of the stack be tested in both drained and undrained conditions prior to implementations.

 

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