The development of a seismic risk reduction procedure for the prioritization of low cost, load bearing masonry buildings

De la Harpe, Charles William Henry (2015-03)

Thesis (MEng)--Stellenbosch University, 2015.

Thesis

ENGLISH ABSTRACT: The Western Cape is one of the most seismically active regions in South Africa. It features geological properties which can develop earthquakes as large as 6.87 on the Richter scale. This poses a serious threat to all of the buildings that are currently located within this region. A recent study has found that typical three-storey Unreinforced Masonry (URM) buildings in the Cape Town area shows a high probability of failure or damage if subjected to such a large earthquake. Many of these buildings can be found in an area of Cape Town called the Cape Flats, housing approximately 11 000 individuals. The structural integrity of these buildings are of concern to engineers since it houses a number of individuals. The purpose of the study was to develop a risk assessment procedure that could be used to assess low-rise multi-storey (2, 3 and 4 storeys) URM buildings in order to determine where the risk of earthquake related damage would be the highest. The risk assessment procedure compared various characteristics regarding the buildings, residents, seismic attributes of the region and the recovery capability of the residents. The result, in the form of a risk rating, enabled the buildings to be prioritized according to their seismic risk. The aim was to develop a comparative model which could be applied to a range of buildings, indicating where the impact of an earthquake would be greatest. This result could then be used for further remedial action (such as retrofitting) where it is needed the most. The risk assessment procedure used an Earthquake Risk Assessment Model (ERAM) which was specifically developed to assess the earthquake risk of each building with the use of 26 factors. These factors would each be individually scored and through the ERAM model would produce a risk rating. The buildings' can then be ranked (prioritized) according to it's risk rating to determine where remedial actions or procedures are needed first.

AFRIKAANSE OPSOMMING: Die Wes-Kaap is een van die mees seismiese aktiewe streke in Suid-Afrika. Dit bevat geologiese eienskappe wat aardbewings met groottes van 6,87 op die Richterskaal kan laat ontwikkel (1 in 475 jaar herhaal periode). Dit hou 'n bedreiging vir baie die geboue wat tans in hierdie streek geleë is. 'n Onlangse studie het bevind dat tipiese drie-verdieping lasdraende steengeboue in die omgewing van Kaapstad 'n hoë waarskynlikheid van faling of skade toon as dit blootgestel word aan 'n groot aardbewing. Baie van hierdie geboue kan gevind word in 'n gebied van Kaapstad genaamd die Kaapse Vlakte, wat vir ongeveer 11 000 individue behuising bied. Die strukturele integriteit van hierdie geboue is van belang aangesien dit 'n groot aantal individue huisves. Die doel van die studie was om 'n risiko-evaluerings proses te ontwikkel wat gebruik kan word om multi-verdieping (2, 3 en 4 verdiepings) lasdraende steengeboue te evalueer ten opsigte van aardbewing verwante skade. Die risiko-evaluering proses vergelyk verskeie kenmerke van die geboue, die inwoners, seismiese eienskappe van die streek en die vermoë van die inwoners om terug te keer na hul alledaagse leefstyl. Die resultaat is in die vorm van 'n risiko-gradering, wat die gebruiker in staat stel om die geboue te prioritiseer volgens hul aardbewings risiko. Die doel was om 'n vergelykende model te ontwikkel wat toegepas kan word om 'n verskeidenheid van geboue te evalueer, en aan te dui waar die impak van 'n aardbewing die grootste sal wees. Hierdie resultaat kan dan gebruik word vir verdere remediërende optrede of prosedures soos versterkings. Die risiko-evaluerings proses gebruik 'n "Earthquake Risk Assessment Model" (ERAM) wat spesifiek ontwikkel is om die aardbewings-risiko van elke gebou te evalueer met die gebruik van 26 faktore. Hierdie faktore word elkeen individueel beoordeel en 'n risiko-gradering word verkry met behulp van die ERAM model. Die geboue kan dan geprioritiseer word volgens elkeen se risiko-gradering om te bepaal waar daar remediërende optrede nodig is.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/97014
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