Browsing by Author "Rabie, Nadia"

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    Alignment of South African National Building Regulation deemed-to-satisfy wall configurations to the loading code
    (Stellenbosch : Stellenbosch University, , 2023-03) Rabie, Nadia; De Villiers, Wibke Irmtraut; Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering.
    ENGLISH ABSTRACT: The revision of the South African wind loading standard, SANS 10160-3 published in 2019, resulted in an increase of design wind load for South Africa of 11 % (Botha et al., 2019). Due to the cautious design restrictions of prior seismic standards, a new seismic loading standard, SANS 10160-4, was developed in 2009. However, since the deemed-to-satisfy walling solutions (SANS 10400-K) of the National Building Regulations (NBR) were created in 2000, they may not satisfy the most recent wind and seismic loading standards. The possible discrepancy between the National Building Regulations and South African loading standards could have an impact on the structural performance of South African masonry buildings. Many low-income housing owners have reported that the structure is inadequate and lacks quality. Furthermore, De Villiers (2019) showed that conventional masonry walls based on the NBR's deemed-to-satisfy solutions fail sustain the required design loads. With this said, there is still currently a housing shortage of 3.7 million (SA Stats, 2019) which is expanding at a rate of 178 000 units per year (Di Lollo et al., 2019). In addition, the government is struggling to meet the moving target and is shifting their policy to providing serviced land only which may increase self-builds. Therefore, it is required to conduct assessments on low-income housing that is subjected to wind and seismic loading according to SANS 10160-3 and SANS 10160-4. To analyse these discrepancies, various low-income housing buildings layouts were designed consisting of the most vulnerable wall configurations permitted by the National Building Regulations taking into account building energy usage, natural lightning, constructability, South African construction practice and skill level. Thereafter, the worst-case wind and seismic loadings according to South African loading standards are calculated and applied to the vulnerable wall configurations through computational modelling, using finite element analysis (DIANA FEA). To analyse the capacity of the wall configurations, the simplified micro-modelling approach was used together with two input parameter sets. The first parameter set represents masonry in South Africa's low-income housing general practice and is obtained through experimental results performed by Fourie (2017). The second parameter set represents the minimum requirements specified by the relevant South African standards. The results revealed that the majority of the deemed-to-satisfy wall configurations fail to meet the required ultimate limit state wind design load. Under ULS-S loading, the study findings indicate that the slenderness of the pier adjacent to the return wall governs the wall capacity. Therefore, SANS 10400-K does not provide sufficient requirements for deemed-to-satisfy panel walls and gable walls to sustain the ULS-W and SLS loading required by the updated wind loading standard of South Africa (SANS 10160-3, 2019) as well as the seismic loading standard (SANS 10160-4, 2017). It is recommended that the minimum required geometry requirements provided by SANS 10400-K (2011) as well as the minimum requirements for material parameters provided by the South African standards should both be increased to the ensure the subsequent structural capacity of the walls exceeds the design load required by SANS 10160-3 (2019) and SANS 10160-4 (2017).