Assessing the Stability of Cable-Reinforced High Bedding Rock Slopes against Rotational Bi-planar Failure

Rotational bi-planar sliding is the most common type of failure in high bedding rock slopes (HBRSs). Prestressed anchor cables are often used to reinforce HBRSs because of their low cost and high efficiency. In this work, a new limit equilibrium method was proposed for evaluating the stability of such cable-reinforced HBRSs (CHBRSs) with respect to rotational bi-planar failure. Tilt-test physical modeling and discrete numerical simulations were first conducted to investigate the mechanism underlying the occurrence of rotational bi-planar failure. A no-block-division mechanical model was then established and the method used to assess the stability of the CHBRS was proposed based on formulae describing force and moment equilibria. Four physical models and traditional 'slice' methods (e.g., the Morgenstern-Price and Spencer methods) were subsequently used to validate the feasibility and accuracy of the proposed method. Finally, the effects of various parameters on the magnitude of the reinforcement effect (anchor location, pretension value, anchorage angle, and joint strength) were investigated. The results obtained using the proposed method are in good agreement with those obtained via tilt-test models and traditional slice methods. The slope has a higher safety factor when the prestressed anchor cable is located closer to the lower part of the slope; however, the anchorage angle of the cable has almost no effect on the safety factor. The proposed method can be used as a useful design aid to help protect HBRSs from rotational bi-planar failure.

Automated summary

A new limit equilibrium method is proposed for evaluating the stability of cable-reinforced high bedding rock slopes subjected to rotational bi-planar failure. The proposed method is validated through tilt-test physical modeling and discrete numerical simulations, and its results are found to be in good agreement with those obtained from traditional slice methods. The location of the prestressed anchor cable has a significant impact on the safety factor of the slope, while the anchorage angle has almost no effect.