Construction of the vertical shaft between the undersea tunnel and the outlet

Taking a step to uplift force and monitoring under chemical grouting

Abstract

In Shika Nuclear Power Plant Unit No.2, cooling seawater from the condenser is planned to be discharged through the undersea tunnel, as well as Unit The vertical shaft connecting the tunnel tip to the outlet caisson was planned to be constructed from the tunnel in consideration of cost benefit and weather condition on the site.
Before constructing the vertical shaft, we injected upward from the tunnel tip to the outlet caisson for dewatering. To prevent the outlet caisson from moving by the grouting pressure, we installed ground anchors and monitored the behavior of them.
This paper describes the action and the results of uplift force by the grouting pressure.