Supports and foundations: variability and design

There are many factors which affect the behaviour both of wood poles and of the foundations which support them. Because both are basically of natural material there is also a considerable coefficient of variation which can be applied to each of the properties. In normal practice a simplistic view is taken of the shape and of the properties of the poles and foundations, yet a simple study shows the wide variations which can occur. Because of this variability, much more concern needs to be given to the partial factors which need to be applied to both poles and to foundations to ensure the correct coordination of strengths. The authors discuss these factors and how they affect design of wood poles