ABSTRACT
Structural fatigue of mine haul trucks is a common problem at many mines, and it is generally recognised that haul route surface roughness is a major factor in structural fatigue. However there have been no practical means available for assessing mine haul route surfaces and maintenance standards have traditionally been based on a subjective assessment. This paper describes a new concept which has been developed to classify haul route surfaces according to the structural fatigue damage caused to the haul trucks operating over those routes. The concept is based on the principle that surface features which twist the frame of the haul truck are the most damaging. Test results are presented to demonstrate the high degree of correlation which exists between twist over the haul truck tyre contact points and strain at critical locations on the haul truck frame. A practical apparatus for directly measuring the twist over haul route surfaces is described. It is shown that the twist information is provided directly, without the requirement for complex processing of data, and without disruption to mine operation. The method is therefore proposed as a new concept for cost-effective mine haul route surface maintenance.
