Tunnel face stability under longitudinally inclined layered rock masses
The present paper investigates the problem of the stability of the tunnel face in longitudinally inclined layered rock masses based upon the upper limit theorem of kinematic limit analysis. For the complex geological conditions (rock stratification, rock layer inclination, i.e.), an analytical model is established and the computational model improves the traditional analysis model, overcomes the disadvantage that cannot consider the influence of rock layer inclination. Furthermore, it shows that the rock layer inclination has a significant influence on the stability of a tunnel face, and the critical angle for the rock layer inclination which leads to the most unstable state is remarked. In addition, we provide normalized diagrams, which allow for a quick assessment of the stability of the tunnel face.