ABSTRACT
It is generally said that mountain tunnels are little damaged by earthquake. However, recent case studies of the damage to mountain tunnels caused by earthquakes also show that they are likely to be damaged when 1) the scale of the earthquake is large, 2) there are earthquake faults near the tunnel or 3) there are special conditions. We collected information on the tunnels which suffered damage from earthquake to study the damage mechanism of mountain tunnels. We analyzed collected data, classified damage patterns and preformed simulation analyses and model tests. Based on the study results, we concluded that we were able to classify damage patterns of mountain tunnels by earthquake into following three patterns; 1) damage to tunnel entrance and portal, 2) damage to tunnels at a fractured zone, 3) damage to tunnels by sliding of fault. We were able to prove these mechanisms by the results of simulation analyses and model tests.
