Etude de l’influence de glissement du portail nord sur la stabilité de tunnel de sidi aich (Wilaya de Bejaia, NE Algérien)

Abstract

This work deals with the stability problem of the north head of the Sidi-Aich tunnel (Bejaia), dug in difficult conditions and often in soils with weak mechanical characteristics. The instability of this tunnel due to the large natural fracturing of the terrain. The empirical recommendations of RMR (Rock Mass Rating) Classification to define the quality of the ground, as well as the method of excavation and to guide the choice of a type of retaining to adapt NATM (New Autrichian Tunneling Method). For this purpose, a calculation method has been developed to model this cracked rock behavior. Called DEM (Distinct Element Method), it seeks to take into account the discontinuous nature of the rocky environment. This method is formulated by the 3DEC calculation mode.