Empirical Vs Discontinuum Analysis and Support Design of Bhatan Road Twin Tunnels (18m X 9.5m), A Case Study

In this paper, analysis and support design of the Bhatan tunnels have been carried out using empirical approach as well as numerical modeling approach. The cross section at particular intervals having a cover of 29m has been considered for the study. The rock mass classification and the support requirements have been determined using the widely used Q system of empirical approach. Stress analysis using Numerical methods being increasingly accepted for design of underground excavation due to their ability to consider most of the complexities and the reliability to produce realistic information. The two-dimensional discrete element modeling using UDEC version is used for stress analysis. The support system has been designed based on the deformations in the rock mass and slip and separation of the discontinuities around the excavation. The adequacy of the support system can be gauged from the reduction in the extent of rock mass failure and deformations. The comparison of the two methods have been summarized at the end.