A Study on the Effect of Heaving on the Soundness of Tunnel Invert in Mountain Tunnels

Abstract: The heaving phenomenon in mountain tunnels affects the stability of the tunnel. Therefore, if heaving can occur even on hard ground, it is necessary to construct an invert. The tunnel-invert is an important structural component for the long-term stability of the tunnel. However, in mountain tunnels in Japan, the heaving phenomenon may occur even if the invert is constructed at the design stage. In fact, there have been reports of damage to invert linings in tunnels where invert linings were installed due to heaving. This paper deals with the effect of the ground pressure acting on the heaving of the invert lining by the numerical analysis. The results suggest that it may be possible to predict the degree of damage to the invert during tunnel operation by comparing the amount of heaving in a serviced tunnel with the numerical analysis in this study. In addition, this result can reproduce the heaving phenomenon in tunnels and can contribute to the design and construction of tunnels and the maintenance of tunnels.