Frame structure analysis model of tunnel lining using nonlinear ground reaction curve

The new Austrian tunneling method (NATM) and the shield tunneling method can be applied to Diluvial and Neogene deposits, on which megacities are located in Japan. However, because the lining design techniques differ between the two tunneling methods, a unified concept for tunnel lining design is needed. To this end, in this study, a frame structure analysis model for tunnel lining design, developed based on the nonlinear ground reaction curve, is proposed. The proposed model can consider the passive and active earth pressure due to excavated surface displacement, including the effect of ground self-stabilization, and the excavated surface displacement before lining installation. In the evaluations of the model's performance, the measured earth pressure acting on the lining at the site of a Diluvial deposit was compared with the earth pressures calculated by the proposed model and the conventional linear model. The results verify that the proposed model can reasonably represent the earth pressure acting on the lining, lining displacement, and lining sectional force for various ground types, ranging from soft ground to stiff ground.