Conclusion

The present study for internal blast loading of Quartzite rock tunnel using CEL model for simulating the TNT blast in Abaqus/Explicit has been carried out. The significant conclusions observed from this study are as follows.
Deep tunnel has been found to be more blast resistant than shallow tunnel. The effect of increase in explosive mass has been quite obvious. However, it has been noticed that this effect is more significant in shallow tunnel rather than deep tunnel. The thickness of tunnel liner plays important role in blast resisting but up to a limit only. Further, increase in thickness will make the section uneconomic and heavier, however, enhance in the blast resistance will not significant. Hence, under any proposed depth of tunnel a study should be carried out for optimum thickness of blast resistant tunnel.