ABSTRACT
A small shallow tunnel in limestone was designed. The axis of the tunnel was nearly parallel to the slope and as well as to the steeply inclined faults crossing the roof and the surrounding rock mass. Long, almost horizontal, tensioned and grouted bolts were proposed as a permanent support. The shear strength characteristics along the faults were also defined by the use of Mindlin’s equations whereas the necessary tensioning of the bolts was numerically calculated in order to generate normal stress upon the faults preventing movement of the rock blocks during and after the excavation. The main objective was to increase adequately the shear strength along weak zones and stabilize the slope, using easily installed, from the side of the slope rock bolts, prior to excavation.
