Civil Engineer in South Africa 

About: Civil Engineer in South Africa is an academic journal. The journal publishes majorly in the area(s): Buckling & Deflection (engineering). It has an ISSN identifier of 0009-7845. Over the lifetime, 159 publications have been published receiving 1545 citations.

Engineering classification of jointed rock masses

Abstract: An engineering classification of jointed rock masses, termed the Geomechanics Classification, is proposed.

A classification system for excavation in natural materials

Abstract: A classification system is proposed which is based on the relevant engineering properties of the ground and which does not allow the method of excavation to dictate the class of excavation. The system provides for the classification of the complete range of materials from the weakest soils to the hardest rocks irrespective of the size, shape or means of excavation. Provision is made to determine the excavation class quickly by means of empirical assessments. To obviate disputes,provision is further made to determine the input parameters quantitatively by standard tests. Some of the currently used classification criteria are briefly reviewed. 'n Klassifikasiesisteem gebasseer op toepaslike grondparameters en wat nie die metode van uitgrawing die uitgrawingsklas laat voorskryf nie, word voorgestel. Die sisteem maak voorsiening vir die klassifikasie van materiale oor die totale spektrum van sagte grond tot harde klip ongeag die grootte, vorm en wyse van uitgrawing. Voorsiening word gemaak om die uitgrawingsklas vinnig te bepaal met behulp van empiriese waarnemings. Om geskille te vermy word voorsiening ook gemaak om die insetparameters kwantitatief met behulp van standaard toetse te bepaal. Sommige van die huidige klassifikasie-norme word kortliks bespreek.

Geological factors significant in the assessment of rippability

Abstract: The geological factors that are significant in the evaluation of excavation characteristics of earth and rock materials are described and a guide to the assessment of rippability by tractor mounted rippers is provided. A rippability rating chart is proposed, utilizing the geological parameters which influence ripping and excavation operations. Case histories are presented which illustrate the point that, although seismic wave velocities may provide an indication of the rippability of a rock mass, the geological conditions must also be considered. The term assessment is used deliberately since it must be appreciated that very often a conclusive answer as to whether a rock can be ripped or not just cannot be obtained. In such a situation, only a field test will decide the issued. (A)

Sediment transport and a reservoir siltation formula for Zimbabwe-Rhodesia

Abstract: Field measurements of the suspended sediment load of rivers draining five large catchments ranging from the driest to the wettest parts of the country have enabled a reservoir siltation formula to be developed for Zimbabwe-Rhodesia. A few below-average annual runoff events and several above average events were sampled, including a 40-year return period runoff for one catchment. Almost every significant discharge during a three-year period was measured on the rivers concerned. The laboratory analysis was facilitated by use of a turbidity meter for measuring suspended sediment - a method particularly suited to rivers carrying large proportions of clay and silt. Data for bed load transport were obtained by bed material sampling and survey of channel dimensions, carried out during the dry season, followed by the use of Einstein's calculation. The transport of dissolved solids was measured so that total losses from catchments could be compared with soil loss and soil production data. An order of magnitude amount of 40 t / km2 / year is suggested as an upper bracket sediment transport value for design purposes, provided the catchment concerned is not undergoing larger than average soil erosion. This figure is shown to be in agreement with previously published data, based on reservoir siltation rates, for parts of the Limpopo catchment, but several times smaller than data for small catchments under heavy human occupation in Tanzania. A reservoir siltation formula allowing for the low trap efficiencies of small reservoirs is suggested.

Proposed procedure for identification of dispersive soils by chemical testing : : technical paper

Abstract: Dispersion influences the erodibility of soils as well as the susceptibility to piping of earth embankments. Although the causes and consequences of dispersion are well understood, the identification of dispersive soils remains a problem. Various physical and physico-chemical methods of identification have been proposed by different authors, but none have been entirely successful. The main objective of this paper is to evaluate the methods currently used for the determination of the dispersiveness of a soil and to single out a procedure that could be applied with confidence for the identification of dispersive soils. Dispersie beinvloed die erodeerbaarheid van grond, asook die stabiliteit van grondwalle. Alhoewel die oorsake en gevolge van die verskynsel goed begryp word, is positiewe identifikasie nog 'n probleem. Verskeie fisiese en fisies-chemiese metodes is deur verskillende outeurs voorgestel. Tot op hede egter was nog nie een van hierdie metodes heeltemal aanvaarbaar nie. Die belangrikste doelwit van hierdie navorsing was om die verskillende metodes wat gebruik word, te evalueer en om 'n metode daar te stel waarmee die dispersiepotensiaal met 'n groot mate van sekerheid geidentifiseer kan word.