Analytical and Numerical Solutions of Tunnel Lining Under Seismic Loading and Investigation of Its Affecting Parameters

Underground structures like tunnels are important elements of transportation, network, and service, which due to being surrounded by the ground and withstanding in situ stresses show different seismic behavior in comparison of surface structures. This paper presents analytical solutions for seismic and static loads in circular tunnels, and then they have been used to evaluate internal forces of lining for a section of Bangkok’s urban tunnel. The problem is solved using numerical analysis of finite difference for both horizontal and vertical acceleration coefficients and the results compared with analytical solutions results. According to the results by increasing the horizontal seismic acceleration, the axial force and bending moment increases. And with increasing the depth of tunnel, the forces of lining increases but vertical acceleration of earth has small effect on stresses. For the in- situ stress coefficient it has been seen that as the ratio is further more away from the number one, the created stress increases in the lining.