Reliability basis for assessment of existing building structures with reference to sans 10160

Abstract

The principles of structural reliability are firmly established to provide the basis for structural performance as incorporated in design standards. Reliability-based procedures provide for variabilities and uncertainties that could reasonably be expected during the design service life of the structure. However, not all possible conditions to which all structures are exposed during such an extended service period can be accounted for effectively and economically at the design stage. The assessment of the reliability performance of an existing structure therefore forms an integral part of structural management and engineering practice. Despite the lag between the development and implementation of a basis for design and assessment of structures, the extensive body of information on structural assessment progresses steadily towards standardisation. This paper provides a review of the progress to provide background information towards extending the scope of South African structural standards to include guidance on structural assessment. The focus is on such developments to include provisions for existing structures in Eurocode, together with related investigations. In addition to a general review of background investigations, interrelationships between the basis of design and assessment for Eurocode (potentially also for South Africa) are considered. The main elements of a standardised basis for assessment are defined, and alternative assessment approaches are presented and demonstrated by representative examples. In conclusion, an outline of a possible development path for implementation in South Africa is provided.