Name: Ryosuke Imamura

Thesis title: Study on the design methods for lining segments in deep ground shield tunnels

Supervisor: Mitsutaka Sugimoto

At deep ground,due to higher self-stabilization and the shortage of back-fill grouting, it is found sometimes that active earth pressure is loaded on the segments. However, present design methods of shield segments can not properly account for active earth pressure.The purpose of this research is to simulate the site data by a new model with the ground spring model which can represent active earth pressure and back-fill grouting rate, and to understand the interaction between the ground and segments, in deep ground. As a result, the validity of this model was confirmed, from which the following can be concluded. 
1) This model can simulate the measured earth pressure and hydraulic pressure acting on the segment at the sites.
2) The effective earth pressure acting on segments, displacement, axial force and bending moment by this model is smaller, compared with that by the existing model.