This paper discusses the results of an Australian Coal Association
Research Program project into the development of a routine analytical
design method for roof support in underground mines. Simple design
tools have been developed using a combination of elastic solutions, free
body diagrams, and pile theory. An approach to the design of roof
support in layered strata based on the ability of bolts to resist shear
stresses is outlined. It is shown that pre-tensioning and angled installation
are effective ways of increasing the effectiveness of bolts in such a
situation. In highly stressed strata, macroscopic failure is predicted and a
design based on the support of surcharged rock wedges is proposed. The
methods are applicable to both coal and metalliferous mines.