Parametric Study of the Effect of Excavated Horseshoe Tunnels on the Maximum Surface Settlement and Inner Forces of Tunnel Lining

Generally, the Earth is under the force of actual stress and any disturbance such as tunnel excavation disarranges the stress condition and surface displacements. If these displacements are not in standard range, it can cause some problems in surface and lower level structures. At the time of tunnel excavation, some parameters such as cohesion, friction angle, elasticity modulus, tunnel diameter, and tunnel space affect the surface settlements and inner forces of tunnel lining. In this study, measured and examined effect of each of the above parameters.
According to the analysis, increase in cohesion, elasticity modulus and tunnel depth cause the surface settlement decrease but increasing the friction angle or tunnel diameter cause surface settlement enhancement. The results are described in detail by graph and table and the results show a significant effect of these parameters on the surface settlement and inner forces.