It is expected to develop the reliable reinforced method to decrease the surface settlement on the shallow tunnel in urban resion. A new pre-lining method which can make the continuous arched body on the top of the face has been developed. It makes a reverse T type body by using the high pressure grouting with three direction nozzle.
The reverse T type body is not only economical shape but also effective function in a complex with the ground. The three dimensional model test chaging the shape of the reinforcement was carried out to investigate the effect of this pre-lining method. This paper describes the result of the model test.