The 200 m long water carrying canal tunnel was excavated for passing the main canal of lower valley Wardha project across the railway line and nearby the habitants on the surface. The tunnel width during excavation was at 8.5 m with the finished width after lining at 7.3 m. The rock mass classification approaches including Barton’s Q and Bieniawski’s RMR was used to classify the rock mass. From these obtained parameters, estimation of unsupported span, the tunnel deformation and the tunnel support pressure were estimated. These parameters were then used to classify the tunnel and estimation of the support requirement including lining. The outcome of these study revealed that the entire tunnel needs to be stabilized by the application of fully grouted 4.0 m long rock bolts of 25 mm diameter and by steel ribs spaced at 0.6 -1.0 m and permanently providing concrete lining throughout the tunnel length. In addition to this, design for smooth wall blasting was also suggested to minimize the blast induced damage and over-break in the tunnel wall. Tunnel was classified considering surface features on the surface and suitable support was recommended.
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