Civil Engineer in South Africa - Volume 24, Issue 6, 1982
Volume 24, Issue 6, 1982
Author H. ScholzSource: Civil Engineer in South Africa 24, pp 239 –249 (1982)More Less
It is disturbing to notice that large differences can occur when designing reinforced concrete cantilever slabs for strength by elastic methods or, alternatively, by ultimate approaches such as the yield-line analysis. The results are therefore reported of a comparison between elastic analysis, yield-line analysis and laboratory tests for reinforced concrete cantilever slabs subjected to point loading.
In essence, the theoretical study embraces a number of different reinforcement arrangements in a slab of infinite length and finite span.
The laboratory tests were performed on three slabs with a length to span ratio of 6 and on three further slabs with a length to span ratio of 8,8. The major purpose of these tests was to measure the actual failure loads for comparison with theoretical results.
A conclusion has been drawn regarding the suitability of the yield-line approach in analysing slabs of the nature investigated in this study. In addition, the serviceability limit state of deflection is discussed in some detail using the load-deflection curves recorded during the experiments.
Source: Civil Engineer in South Africa 24, pp 251 –257 (1982)More Less
The results of a survey of current stormwater drainage design practice are presented. The survey, undertaken by the National Building Research Institute during 1979, took the form of a questionnaire sent to various design offices in the Republic.
Questions were pored relating to design philosophy, design recurrence interval, frequency of observed malfunctions, hydrological design methods and minimum allowable pipe diameters. An example of a design for a hypothetical urban sub-development was also requested.
The results show a common design philosophy throughout the country but highlight wide variations in the application of design techniques.
Die uitslae van 'n opname van huidige stormwaterdreineringspraktyk word voorgestel. Die opname wat deur die Nasionale Bounavorsingsinstituut in 1979 onderneem is, was in die vorm van 'n vraelys wat aan verskillende ontwerpskantore in die Republiek gestuur is.
Vrae is gestel oor ontwerpsfilosofie, tussenposes van ontwerpsherhaling, frekwensie van waargenome foutiewe werking, hidrologiese ontwerpmetodes en die minimale toelaatbare deursnee van pype. 'n Voorbeeld van 'n ontwerp vir 'n veronderstelde stedelike onderontwikkeling is ook gevra.
Die uitslae toon 'n algemene landwye ontwerpfilosofie aan maar belig groot variasies in die toepassing van ontwerpstegnieke.
Author M.D. RadfordSource: Civil Engineer in South Africa 24 (1982)More Less
A method for calculating the volume of a heap of material is described. The formula for an ellipse is used to calculate the pianimetric areas of the heap. The application of the method to a heap with a circular shape will nevertheless give results to a similar degree of accuracy.
'n Metode word bespreek om die volume van 'n hoop materiaal te bepaal. Die formule vir 'n ellipse word gebruik om die oppervlaktes van die hoop, in plangesien, te bereken. Indien die hoop sirkelvormig is, sal die metode ewe noukeurigeresultate lewer.