Slope Stabilization of Twin-Tubes Tunnel Portal by Anchor Bolts Support System

It is not known in the literature why the behavior of rocks incurs the tunnel excavation and it remains unclear for what has been calculated in the initial studies. That’s why the most important thing to consider in tunnel construction works is to monitor rock mass behavior. The finite element method (FEM) can also analytically represent the static and dynamic behavior of the rock mass. Concretely, this makes it possible to calculate the behavior of very complex objects numerically. The present study embraces a geophysical prospecting which was carried out by the method of surface seismic tomography to reveal the lithology of the different formations and their geometry and the variation in speed of the subsurface formations at the level of the South portal of the Texana tunnel on Jijel province, in Algeria. The paper also consists in making a two-dimensional numerical study of the stability of the tunnel portals with the Phase.2 2D program. On the other hand, the calculation results will be compared with in-situ surveying to strengthen the numerical modeling. It can be concluded that the Anchor Bolts Support System gives good results in terms of displacement of the rock mass and satisfactory stability in terms of collapse analyzis of the tunnel portals.