Development of 2D design charts for rock slopes susceptible to slide-head toppling failure.

Past research has always assumed that when it comes to toppling analysis, the base friction is
equal to the inter-block friction resistance. However, with recent advancements in research, it has
been observed that the failure plane may counter-tilt and daylight anywhere else other than the
presumed toe of the slope. With this in mind, it is also possible for the two friction resistances
(base and inter-block) to vary. This paper presents development of 2-dimension design charts
based on the assumption that the base friction is not equal to the inter-block friction resistance
(𝜙𝑝 ≠ 𝜙𝑑). Observations made on the design charts reveal that the charts can be applied on both
the initial and counter-tilted failure planes. Furthermore, positive values for zeta (𝜁) have been
observed for weak plane (ψp) angles that are less than the base friction and vice-versa for values
of ψp greater than base friction.