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.
Mohsen Naghibi; Morteza Kolahdouzan
Abstract
A two-dimensional two-phase numerical model is developed to predict transport and fate of oil slicks which resulted the concentration distribution of oil on the water surface. Two dimensional governing equation of fluid flow which consists mass and momentum conservation was solved using the finite difference ...
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A two-dimensional two-phase numerical model is developed to predict transport and fate of oil slicks which resulted the concentration distribution of oil on the water surface. Two dimensional governing equation of fluid flow which consists mass and momentum conservation was solved using the finite difference method on the structured staggered grid system. The resulted algebric equations were solved by use of ADI (Alternating Direction Implicit) technique. In addition the wind speed and coriolis effect can be included in the current hydrodynamic model. Transport of oil slick was pridect by the two dimensinal particle tracking approach consists of Lagrangian method for advection processes, the Random Walk technique for horizontal diffusion process and the empirical equations for the fate processes. Different processes are considered and included in the developed model which are: advection, spreading, turbulent diffusion, evaporation, dissolution, vertical dispersion, emulsification, shoreline deposition and adsorption by bed sediment. Oil is divided into eight hydrocarbon components so this model is capable of considering the oil composition of some fractions with theirs characteristics. Comparison of results with analytical solution for standard problems represent a good degree of similarity. In addition, model is used in a case of oil spill in Persian Gulf to represent the application of model to real case studies.
