Simulating the Effects of Projectile Explosion on a Jointed Rock Mass Using 2D DEM: A Case Study of Ardebil Mianeh Railway Tunnel

Considerations on the explosion resistant design of special infrastructures have increased in the recent years. Amongst the various types of infrastructures, road and railway tunnels have a unique importance due to their vital role in connection routes in emergency conditions. In this study, the explosion effects of a projectile impacting on a railway tunnel located in a jointed rock medium has been simulated using 2D DEM code. Primarily, a GP2000 projectile has been considered as a usual projectile and its penetration depth plus its crater diameter were calculated in rock mass. The blast pressure was, then, calculated via empirical formula and applied on the boundary of crater as input load. Finally, the wave pressure propagation through the jointed rock medium was investigated. In part of the study a sensitivity analysis has been carried out on jointed rock parameters such as joint orientation, dynamic modulus and ding ratio. Their effects on tunnel lining axial force as well as bending moment have also been investigated