Abstract
Rock tunnels suffered severe damage from recent large earthquakes in Japan, despite the empirical knowledge that tunnels tolerate earthquakes better than surface structures. Seismic design for rock tunnels have therefore become a fascinating subject for many tunnel engineers. However, even basic behavior of tunnel during earthquake has not been fully understood due to lack of actual seismic data. In this study, the authors installed dynamic measurement system including accelerometer and strain meter at two actual road tunnels. The major results include: Seismic intensity at the tunnel is smaller than that on the ground surface. Seismic intensity at the tunnel is almost the same as that in the surrounding ground.
