جستجوی مقالات مرتبط با کلیدواژه « rock slope stability analysis » در نشریات گروه « مهندسی معدن »

The recent studies have shown the importance of the role of intermediate principal stress in design process of geomechanics projects. Therefore in this paper, considering the triaxial unified strength failure criterion, the Bishop method was developed. Moreover, based on the numerical modeling results, two diagrams for slope stability analysis were presented. In large-scale open pit mines, one of the major issues during design is maximizing the net present value of the mine. One of the most important factors in this regard is the optimum slope angle of the mine. Generally, in rock slope stability analyses, the considered failure criteria are biaxial, thus in analysis process, only the maximum and minimum principal stresses of medium are considered. Actually, in most cases, the effect of intermediate principal stress is ignored completely, while recent researches have shown that the design and calculation of safety factor, regardless of the intermediate principal stress effect, is conservative and can have a significant effect on the economic conditions of the project. One of the triaxial failure criteria is the unified strength failure criterion. It consists of a wide range of solutions based on different failure criteria such as the Mohr-Coulomb failure criterion and Generalized Twin Shear Stress yield. In reality, based on this failure criterion, considering the intermediate principal stress effect, the amount of geomechanical properties of rock mass; such as internal friction angle and cohesion are increased and consequently, the safety factor of stability condition will be larger than the obtained safety factor from biaxial failure criterion. Therefore, the main purpose of this paper is development of a slope stability analysis method that considers the effect of intermediate principal stress. In this research, considering the circular failure conditions for soil and rock slopes, the Bishop's equilibrium method was extended based on the triaxial unified strength failure criterion. Also, for analyzing the stability and calculating the optimum slope angle, new diagrams were presented. The results showed that, without the intermediate principal stress effect, calculation of safety factor for investigating the slope stability condition is conservative and the net present value of mine is decreased consequently. Moreover, the sensitivity analyses showed that the amount of intermediate principal stress effect on the safety factor is not a function of the resistance properties of rock and soil.

Rock slope stability analysis with the use of analytical and numerical approaches is usually a complicated engineering task because of complex behaviour of the rock mass and also of the various affecting parameters. On the other hand, even though the wide application of empirical methods, they don’t have an acceptable accuracy and efficiency in all situations due to the consideration of the specified influencing major factors. The Rock Engineering Systems (RES) is a systems approach which can be considered as a suitable method for rock engineering analyses and classifications particularly in areas with complex environment and multiple affecting parameters. In this method, the interactions between the system’s parameters are analyzed and then the effect of each parameter on the subject (system) is considered. The aim of this paper is to utilize the RES approach to classification of rock slopes in Khosh-Yeylagh mountainous road between Shahrood and Azadshahr cities in Iran. In this way, the study region and its conditions have been visited and some stations on the rock slopes have been selected. Then, the key steps of the mentioned approach such as selection of the most important parameters generating the instability, establishment of the interaction matrix and its coding, setting up the classification menus, defining the instability index in the form of a mathematical formula have been consecutively followed. Then, the experimental data of rock and rock joint physical characteristics were achieved and the indices for each slope were calculated. In this manner, the rock slopes in the stations were classified from the instability point of view. Finally, as a preliminary validation on the utilization of systems approach in the study region, the stability of investigated rock slopes were analyzed using an empirical method and the results were compared. The comparisons showed a rather good coincidence between the given classes of two methods. The results of this research showed that the utilization of the systems approach could be considered very useful in rock slope stability analysis specifically in large scale problems with various affecting parameters.