Mehdi Mousavi; Ali Reza Yarahmadi Bafghi; Hamid Reza Bakhshi
Abstract
In the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. In 2-D analysis, effect of convex and concave walls are ...
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In the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. In 2-D analysis, effect of convex and concave walls are neglected, however concave slopes are believed to be more stable than straight walls due to the lateral restraint provided by material on either sides of a potential failure in a concave slope. In open pit mines with general tendency to increase the wall angle, this point is really important. In this study slope stability of western wall of Sarcheshmeh mine in its extension plan is analyzed using 3-D distinct element method (3DEC). For stability analysis, west wall is divided into three structural regions according to the rock type. Rock and joint strength properties are determined from previous and new laboratory tests. Also in Andesite (dominant rock of the west wall) geometrical properties of joint sets are determined. Consequently Slide5.0 software is used to identify rock mass stability and effect of disturbance factor, underground water, horizontal seismic acceleration and rock type on wall stability. In the next step, the mine geometry is modeled in 3DEC and wall stability is investigated in different locations. Results obtained from 3DEC prove failure of several benches at the toe. Also results show drainage may improve stability in some zones but there would still be smaller failures in the toe.
Majid Meybodian; Hossein Memarian; Mehdi Zare
Abstract
Sarcheshmeh copper mine, with the final reserves of 828 million tons of sulfur ore and average grade of 0.74%, is known to be the largest open pit of Iran and most probably the second largest copper mine in the world. This mine is located in the seismotectonic zone of Central-Iran, and 23 Km away from ...
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Sarcheshmeh copper mine, with the final reserves of 828 million tons of sulfur ore and average grade of 0.74%, is known to be the largest open pit of Iran and most probably the second largest copper mine in the world. This mine is located in the seismotectonic zone of Central-Iran, and 23 Km away from the 150 Km long Rafsanjan active fault.In this study the vulnerability of the west wall of the mine, which is more susceptible to sliding, is determined. First, the seismic hazard probability was calculated by defining seismic sources and determination of seismicity parameters. Then the most effective source in seismic hazard is determined by seismic hazard deaggregation. The Newmark displacement of the west wall is calculated by the critical acceleration and Arias intensity. Finally, the mine vulnerability and seismic risk for this site, along with the probable earthquakes, is calculated. The seismic risk of this site is estimated to be 0.07 of the overall value of the mine.