Calibration of safety factors for steel construction in Tanzania

Safety factors are based on statistical properties of materials and load actions in the relevant countries, for instance, the British standards are established to suit well the materials and loads action in Britain, when the British standards are to be used in another country, some modifications have to be done. This research establishes the reliability and thus the Partial Safety Factors of structures designed to BS 5950 but constructed in Tanzania. This was carried out through lab tests and data collection of commercially available steel sections. This information was used for the reliability analysis of structures, and thus determination of Partial Safety Factors. The reliability index obtained from the collected test certificates was 4.4296 which is slightly lower than the target reliability index value which is 4.8. The value obtained from the laboratory tested result, was 1.8974, a value which is very low compared to the target reliability index. The values of the partial safety factors for steel resistance, for the test certificates results, were 0.898. This value was so close to the value of 1.0 used in the design code, but as for the laboratory tested sections result, a higher value equal to 1.353 was obtained. So, for safe use of BS 5950, the values of the partial safety factors for steel design should be raised.