Three-Dimensional Numerical Modelling of Pre-Support System in front of Tunnel by Different Approaches, Case Study

This paper investigates the effect of the method of applying pre-support in the numerical modeling of tunnel and ground interaction. Two main numerical approaches of linear pile and equivalent zone elements were considered for the modeling of pre-support in front of the advancing tunnel face. Both of these approaches were applied for one of the Tehran-Shomal Freeway as the case study of numerical modeling. The results of numerical models were compared to investigate the effect of pre-support modeling approaches. The vertical deformation of numerical models with different approaches shows a meaningful consistency; therefore, it is concluded that both of these methods of linear pile element and equivalent zone element can be applied to numerical modeling demands for other studies.