The work presents the results of the slope stability analysis in jointed rock mass using equivalent continuum model. The stability analysis of a large slope is carried out using the concept of practical equivalent continuum model using joint factor and non-linear hyperbolic model. The natural profile of 359m high slope at Kauri side of Chenab river bank in Jammu & Kashmir, India has been considered as a case study in the analysis. Slope stability analysis have been carried out for both static and dynamic/earthquake conditions. Both pseudo static approach with appropriate acceleration coefficients and the complex dynamic analysis of earthquake shaking using complete acceleration history of a real earthquake has been applied at the base of the slope. Factor of safety were calculated using shear strength reduction technique considering equivalent continuum approach in the pseudo static approach.
This paper focuses primarily on the stability of a natural 359m high slope in Jammu & Kashmir. In the present work, the stability analysis of the right abutment slope at Kauri side of Chenab river between Katra and Laole, in Jammu and Kashmir, India is simulated using FLAC as a plane strain problem. Further seismic analyses have been done using pseudo static approach and also by applying complete time history of a real earthquake. Pseudo static approach is relatively simple and straight forward with less time consuming but it can not really simulate the complex dynamic effects of earthquake shaking through a constant unidirectional pseudo static acceleration. The sudden ground displacements due to the earthquake motion induce large inertia forces in the slope which alternate their direction during the earthquake. The effect of these pulsating stresses, on the slope behavior has been studied. These inertial forces in certain zones of the slope are sometimes high enough to bring down the factor of safety below unity and lead to a slope failure. To simulate the complex dynamic effects of earthquake shaking realistically complete acceleration time history of a real earthquake has been applied at the base of the slope. Strong motion data of the moderate size earthquake of occurred magnitude 6.5 in the Uttarkashi region of Western Himalayas on October 20, 1991 has been used for this analysis. The strength under dynamic conditions is a function of the entire time history of the stresses developed as well as the stress intensity during the earthquake.The magnitude of the deformations that developed is dependent upon the applied time history of the inertial forces, therefore the knowledge of this variation of the inertial forces with time will certainly help in design along with the deformation induced in the slope due to the earthquake forces.
The Chenab river forms about 360m deep gorge in aV-shaped valley in the area between Bakkal and Kauri villages. The width of the river is about 150m at river bed level and the level of river bed is 488 m.