| In Japan, there are some existing road tunnels in service that have suffered serious damage such as compression or shear failure on their concrete lining by the action of excessive earth pressure. In these damaged tunnels, the load bearing capacity of the concrete lining has deteriorated and it becomes a crucial problem to rehabilitate these damaged tunnels to secure safety of tunnel users.Therefore development of the method to restore the load bearing capacity of damaged tunnel concrete lining has been growing in demand and inner reinforcement such as installation of thin steel plate, steel arch support onto the damaged concrete lining is expected as one of the effective method. However, the mechanism of the effect of these inner reinforcements onto the damaged lining has not been clarified yet and establishment of the design method of inner reinforcement is necessary to apply this method widely to the damaged tunnel.In this paper, model experiment using full-scale tunnel concrete lining specimen was carried out to clarify the mechanism of the collapse of tunnel concrete lining by the action of excessive load on crown. Furthermore, model experiments using full-scale damaged tunnel concrete lining specimens with inner reinforcement such as thin steel plate and steel arch support were carried out to clarify the effect of these reinforcements on the load bearing capacity of the damaged concrete lining. Finally, the mechanism of the effect of the inner reinforcement on the recovery of the load bearing capacity of the damaged concrete lining is discussed. |
