Open Cut » Maintenance & Equipment
Investigations conducted on dragline boom structures by MTI have shown that there has been a lack of clear understanding of the main parameters affecting the strength and loading of this structural system. The loading and design criteria used for the original design of the structures are not available either to the owner’s or to the engineering community who are providing technical services. Various studies conducted by MTI showed that the boom and mast structural system in most draglines had the potential to work at higher loads than they were currently operating.
Most engineering structures are currently designed using the Limit State Design (LSD) approach. However, the existing LSD standard does not cover dragline structures. The ACARP funded projects investigate the procedure for assessing dragline structure by utilizing the limit state approach with a view to achieve a more accurate and reliable assessment of the capacity of the structure to further increase performance .
MTI believes that the design of dragline structures should be performed using rational and reliable assessment procedures, based modern structural engineering practices. This project developed such a procedure for assessing these structures by utilizing a LSD approach.
The project concluded with the development of a well defined procedure to assess dragline booms particularly for their strength or capacity. The main features of the methodology are detailed in the final report.
The assessment by LSD approach is likely to produce more favourable capacity assessment if long-term data is available to compare the validity of the method with the load and capacity factors that are used in this analysis. MTI believes an engineering committee representing the mining industry should be established to define the most appropriate β factors for routine use in design and assessment of dragline boom structures.