Analysis and Design of Long Cable Bolts for Common Cut-Slope
Instability Problems in Brittle Rock Open Pit Mines:
The Sepon Copper Mine Experience
Arnulfo B. Santiago, BSc Geol., MSc. GtE
Senior Technical Advisor - Geotechnical Engineering
Sepon Copper Mine, Mining and Metals Group - Lane Xang Minerals Ltd.,
Vilabouly District, Savanhnakhet Province.,Lao PDR
The stability of mine open cut-walls depends largely on the shear strength properties of a rock mass, the structural discontinuity orientations, and the engineering interventions applied for sustainable stability that does not compromise safety and environmentally sound working condition. Sustainable stability of open pit cut-walls is a very important factor in maintaining a balanced safe and seamless profitable mining operation.
Rock bolting technology has been popular ground control method and widely used in the stabilization of cut-walls particularly in the mining industry long before any advanced mining technology was introduced. There had been several types of materials in use and means to support and stabilize both open pit cut-slopes and underground workings using rock bolts even before the technology was improved and become popular to be a life-saving methodology and an important factor to increase mining profits as well.
Today, rock bolting technology has become even more popular as one of the most important rock supporting systems in mining and geotechnical engineering and comparably has far been more economical than other engineering ground supporting techniques because it can be applied with less material and manpower utilization and it requires only basic installation equipment. In addition, rock bolting can be used in a number of applications for varying geotechnical conditions and rock-supporting requirements.
The application of cable bolting technique on blasted cut-slope stabilization in the Sepon Copper Mine in Lao, PDR in its open pit mine provides an overview of an effective and efficient support system because it utilizes the nature of the rock mass to reinforce itself by just the application of counteracting internal stress. In Sepon, previous studies on appropriate methodologies and types were developed for effective rock slope supporting requirements under varying geological and geotechnical conditions. However, in anticipation to problems with the support systems which may arise, it may become very difficult and may require appropriate expertise to analyze whether the problems are caused by deteriorating geological conditions, poor installation practices, or malfunctioning support system. Correct diagnosis of the causes can enable the design engineer to take the appropriate remedial measures to prevent the same problem from recurring, thus minimizing future potential ground control problems, property damage, opportunity loss, and fatal accidents.