Analysis of Failure Mechanisms and Design of Support for Jointed Rock Slopes of Chenab Bridge

The jointed rock mass of the Himalayas presents significant challenges for infrastructure projects due to their complex geology and tectonic plate movements. This study focuses on the jointed rock slopes supporting the Chenab railway bridge abutments, which were susceptible to various types of failures. A comprehensive method was implemented in this study to identify the potential slope failure types and quantify the risk associated with these jointed rock slopes. Field investigation results were used to estimate the stiffness and strength properties of the joints and rock mass through empirical relations. Key joint parameters, properties, and slope angles were utilised for kinematic and wedge analysis to identify the potential planar, wedge and toppling events. Based on these rigorous analyses, rock bolts were recommended as a support measure. On one hand, the rock mass was represented as an equivalent continuum in finite element and limit equilibrium analyses, which revealed no local failures. On the other hand, three major joints were explicitly modelled using the Mohr–Coulomb constitutive relation, while the Hoek–Brown model was used to represent the intact rock matrix between the joints. The novelty of this paper lies in its explicit modelling of major joints, which was not done by most of the earlier researchers. This approach successfully identified the local failures and allowed for comparisons with other analysis methods. The findings were applied to calculate displacements, shear strains, and to design a support system incorporating rock bolts for the right abutment central slope of the Chenab railway bridge.