Journal of the South African Institution of Civil Engineers (Apr 2009)
The issue of personal safety on dolomite: a probability-based evaluation with respect to single-storey residential houses
Abstract
In refining the principles supporting the safe and judicious use of land, the Council for Geoscience (CGS) is researching the use of a risk-based evaluation of the influence of development density on personal safety. This paper considers single-storey dwelling houses and is the first in a series that will also consider multi-storey and mixed-use developments. In much the same way that rainfall statistics are used to calculate flood events in order to control development by restricting it to above a fixed return period flood line, is it proposed to expand and apply the frequencies of sinkhole occurrence in order to arrive at a more rigorous expression of acceptable development densities for the eight "Inherent Risk Classes". A number of probability concepts are used in determining the development density. Depending on the incidence of each probability, it has been possible to determine the risk associated with development on dolomite for a single-storey dwelling. Recommended population densities are proposed for each Inherent Risk Class, with the exceptions of Risk Classes 6, 7 and 8, where no residential development is catered for, in line with industry standards.