INFLUENCE OF SPACING AND PERSISTENCE OF JOINTS ON ROCK SLOPE STABILITY

Abstract

Landslide, one of the natural hazard, which refers to one of the kind of “mass wasting” and results in tremendous loss in the lives, property, engineering construction, which occurs due to earthquake, volcanoes and such other reasons. In comparison to other other parts of the world, it is mountainous region which are more susceptible to landslide, many reasons are there behind such massive failure one of the major reason behind the landslide is the spacing, length and persistence of joints. Joints which are one of a kind of discontinuity is reason behind the rocks weakness, deformability and movement in the rockmass they are nano fractures or fractires without dispalcement ,or these are the planes of seperation. So, these three parameters plays great role in defining the stability of a slope. Though slope stability varies with different rock types. Here four rock types Quartzite, Slate, Phyllite and Basalt are taken into consideration and spacing, length and persistence changes has been studied into it. And then slope stability has been observed. Where slope means any inclined surface and stability to that of inclined surface is considered as slope stability. This inclined surface can be natural or unnatural. Natural slopes which forms by the natural processes like weathering / erosion and occur naturally and they are present in hilly areas. Artificial slopes which are engineered by humans forms due to human activities on the basis of their requirements like for the sides of cuttings ,construction of road ,railways line etc. then due to slope instability there occurs various types of slope failures like toppling, falls, slides, lateral spreads, flows. So for avoiding such failure slope stability analysis is also required, rock slope stability analysis is executed to judge the safe and functional model of excavated slopes ,for natural slope their equilibrium conditions. It is the pattern of discontinuity which governs the type of rock failure. Methods which assess the stability of a rock slope of jointed rocks are kinematic analysis method, the empirical method, the limit equilibrium method, the upper and low bound method, the finite equilibrium method , and the discrete element method. Numerical modelling is an effective way for the performance investigation. Basically it is a mathematical depiction of a physical nature centered on relevant hypothesis also easy suppositions. Many equations cant be solved directly so with the help of numerical modelling the solutions of such equations can be get though approximately. For simulating the behaviour of rockmass with or without rockbolting it is numerical modelling which is widely used and for simulation and calculation of stresses, pore pressure and displacement of rocks finite analysis is used uses stress reduction method (SRM) which is based on FEM, it evaluates the slope stability by giving Factor of Safety. For calculationg it phase 2 software of rocscience has been used ,RS2 (phase 2 ) is a especially flexible 2D finite element program for both rock and soil. Here RS2, R = Rock and S = Soil which is a 2D elasto-plastic finite analysis programme that is used for plotting both subterrestrial or on earth excavation..Different engineering projects like excavation analysis, or excavation design, slope stability, groundwater seepage ,consolidation, probabilistic analysis software RS2 is used. Thus civil, mining, above the ground, stress/deformation or, support effectively analyzed by RS2. Multi-stage models can be analyzed with ease, tunnel construction above it, open pit mines, embankments, surface excavation, dynamic analysis, foundation, consolidation ,groundwater seepage and more.