CONVERGENCE MEASUREMENT FOR MAINTENANCE IN SEIKAN TUNNEL

Abstract

After the completion of Seikan Tunnel, maintenance at the undersea portion has been carried out by Japan Railway Construction Public Corporation.
Long term monitoring for deformation of the lining and seepage water is being per formed to assure the tunnel's safety. Three dimensional measuring system has been introduced for convergence measurement. The seepage volume that depends on pore water pressure is on the decrease since the tunnel's opening.
This paper mentions three dimensional measuring system by electro-optical distance meter, the convergence measuring results and the volume change of seepage water.