Civil Engineer in South Africa - Volume 27, Issue 7, 1985
Volume 27, Issue 7, 1985
Author G.W. DonaldsonSource: Civil Engineer in South Africa 27, pp 341 –345 (1985)More Less
The papers in this volume are devoted to geotechnical engineering in South Africa and more particularly to specific problems encountered in this region and their treatment. It is, therefore, appropriate to review the development of the art and science of this branch of civil engineering, with particular reference to the local scene as the introduction to this.
Author H.F.W.K. ElgesSource: Civil Engineer in South Africa 27, pp 347 –353 (1985)More Less
The nature and occurrence of known deposits of dispersive clays in Southern Africa are described. The main testing procedures for the identification of these clays are given and it is stressed that all clays considered for construction should be tested for potential dispersiveness. Methods of constructing safe and economic structures with dispersive clays are also given with references to some case histories.
Source: Civil Engineer in South Africa 27, pp 355 –365 (1985)More Less
Recent infrastructure developments, primarily along the Natal coast for roads, railways and harbours, have highlighted the significant problems of settlement and stability of embankment and structures on soft clays. Soft clays are not a problem specific to South Africa, and the depositional history, engineering geological and geotechnical properties are similar to those for recent alluvial deposits elsewhere. Nevertheless, there are differences. Probably the most notable is that the alluvial deposits tend to be extremely variable, with sand, silt and clay strata being juxtaposed in a complex pattern both laterally and vertically. This leads to difficulties in ensuring adequate investigation of the strata, which in turn leads to problems of realistically predicting times for settlement. This review discusses the identification, analysis, design and construction on soft clays, giving particular attention to those aspects pertinent to local practice.
Source: Civil Engineer in South Africa 27, pp 367 –401 (1985)More Less
This paper reviews the background and extent of the expansive soils problem in South Africa. The origin of expansive soils is discussed and indicators of heaving conditions which should be recorded during the site investigation are identified. An appraisal is given of the traditional and more recent methods of heave prediction and the selection of suitable foundation types is reviewed. Recommendations are provided for the design of stiffened raft foundations.
Author K. SchwartzSource: Civil Engineer in South Africa 27, pp 379 –393 (1985)More Less
The paper reviews the state of the art of current engineering practice in South Africa with regard to soils which have a collapsible fabric. This includes a discussion on the collapse phenomenon and the distribution of soils with a collapsible fabric in South Africa. The development of procedures to identify collapsible soils and to quantify collapse is presented. Consideration is also given to engineering solutions to the collapse problem.
Author F. von M. WagenerSource: Civil Engineer in South Africa 27, pp 395 –406 (1985)More Less
Damage to structures and loss of life have been far more severe on dolomite than on any other geological formation in South Africa. The subsidence which occurs on dolomitic terrain following development or during dewatering has given dolomite a notorious reputation and many developers have become reluctant to build on it. The problems experienced in this country have led to the pioneering of investigation and founding methods for dolomite sites. In this paper methods of site investigation best suited to the different types of dolomite site are presented. A method of classifying the site in terms of overburden thickness is given, followed by a review of the evaluation methods in use. The paper also discusses various methods of construction.