Alteration of Ground Motion Acceleration at Ground Level Due to Tunnel Excavation

Underground tunneling is one of the alternative solutions to diminish traffic congestion in large cities. One of the most important effects of tunneling is the displacement of the ground surface, the settlement around the tunnel, and the variation in earthquake acceleration. The performance and behavior of underground structures have been studied by several researchers, but the impact of tunnel excavation on earthquake records and its effects on structures above the ground level have received less attention. This research emphasizes changes of earthquake acceleration at the ground level, structural response and Fourier spectrum by excavating a horseshoe tunnel. Results show that digging a horseshoe tunnel will change the characteristics of the earthquake record at ground level.