Best practice of crane support structures design : an expert survey
Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2007.
Research on cranes and crane support structures has been completed at Stellenbosch University’s Structural Division. In order to link the research already completed with that which is practically relevant, an industry related expert survey was proposed. Consequently, the research title is “Best Practice of Crane Support Structures Design – An Expert Survey”. The primary objective of the study is to complete research, which can be used at a later stage to compile a “best practice” guideline for support structures design. The expert survey allows practical experience and opinion to be gathered from experts. The primary drawback being the uncertainty involved in such opinionated research material. For this reason an attempt is made in the thesis to apply a scientific approach, in order to attain rationally defendable results. The survey was conducted using interviews with experienced crane support structure designers and crane manufacturers in South Africa. The experts were then rated according to their answers to seeded questions, the number of colleague recommendations they each received and the years of experience each expert has. The expert opinion was subsequently combined using the expert ratings as weights. To further improve the scientific rationale behind the results, several of the topics mentioned by the experts were verified using related literature - thereby validating the use of the combined expert opinion for this research. The results obtained from the survey and verification process are regarded as useful to the objectives of the study. Information concerning pre-design specifications, loads and actions, structural analysis, design, design details and fatigue was compiled. The direct results are tabulated in an appendix and commentary, based on the expert opinions, is provided. A failure investigation was also completed with less success than initially intended. This was due, in part, to confidentiality issues and a lack of failure information easily accessible to the experts. For this reason the results of the failure investigation focuses more on various failure mechanisms. The success of the survey indicates that expert opinion is a useful tool for research. Furthermore, the minor differences in expert opinion, when compared to information obtained from crane support structure literature, indicates that the expertise in the South African crane support structure design is at an international standard.