Assessment of the dynamic stability of the portals of the Dorukhan tunnel using numerical analysis

摘要: Abstract Instability problems may arise during the construction and operation of tunnels depending on quality rock mass. In particular, determining instability at portals a tunnel is utmost importance excavation tunnel. Slope rockfalls are most frequent that be encountered portals. Such can triggered by dynamic effects such as earthquakes, blasting, etc. This study investigates stability Dorukhan Tunnel connecting provinces Zonguldak Bolu in close vicinity North Anatolian Fault Zone (NAFZ), which well-known strike-slip 1500 km long fault. The effect an earthquake occur NAFZ extent failure has also been studied numerical analyses. analyses, three-dimensional analysis computer code, based finite difference method, used. According to results Devrek portal was found more stable than Mengen portal. Moreover, it that, for acceleration values wave higher 0.5 g , slopes areas far 20–50 m from entrance suffer serious damage. Wave propagation perpendicular axis established cause damage around openings compared parallel axis.