A STUDY OF THE MECHANISM OF FLEXURAL TOPPLING FAILURE OF ROCK SLOPES

The mechanism of flexural toppling failure of jointed rock slopes has been investigated through a series of centrifuge experiments conducted on models manufactured from two types of materials (brittle: a sand-g ypsum mixture; and ductile: fibre-cement sheeting). The basal failure plane observed in the centrifuge models, has been found to emanate fro m the toe of the slope, and orient at an angle of 12 to 20 degrees upw ard from the normal to the discontinuities. A theoretical model based on a limiting equilibrium approach (Aydan and Kawamoto, 1992) has been adopted to analyse the centrifuge test data. After calibration, the m odel was found to accurately predict the failure load for all the test s reported in this study. Using this model, a set of charts has been p repared to assist with the analysis of slopes susceptible to flexural toppling.