*Department of Civil Engineering, National Institute of Technology, Karnataka, India
**Department of Mining Engineering, National Institute of Technology, Karnataka, India
Online published on 19 December, 2013.
Tunnel serves various purposes including transportation. Case study of an underground metro rail project involving different strata conditions was taken up for the study. Modeling was carried out at three different cross sections of tunnel, using 3DEC software, incorporating the strata characteristics, and stability of tunnel was assessed with and without support. Effect of building loads was also analysed. Observations were made about the behaviour of tunnel under given conditions for vertical displacement, at points like crown and floor of tunnel, and on the surface. Minute displacement of 0.52 mm was observed particularly where the tunnel is completely passing strong rock at Chainage 9345 m. Tunnel is passing through moderately weathered rock at Chainage 9295 m, and the analysis resulted in a displacement of 4.19 mm without support, which subsequently reduced to 0.32 mm after lining.
Underground metro, 3DEC, vertical displacement, building loads
