MODEL TESTS FOR EARTH PRESSURE ACTING ON PRE-LINING TUNNEL

It is important to prevent surface settlement and stabilize cutting face in a shallow overburden or a soft ground tunnel, which is called urban NATM. The pre-lining method, in which arch-shell linings were formed ahead of the cutting face prior to excavation, has been applied to some construction site. However, the design of this method is not established. This paper describes results of model tests to investigate earth pressure acting on the pre-lining. It is clarified that acting earth pressure changes during deformation and settlement of the pre-lining, and that the axial force of the pre-lining is uniform in a flexible pre-lining.