The basement and tower block for the proposed South African Transport Services computer centre and office block is to be constructed in Braamfontein in deeply weathered Ventersdorp lava. The new basement will be 26 m deep and the tower block will consist of 40 storeys above street level. The soil profile on the site consists of a residual soil up to a depth of approximately 57 m, whereafter soft rock occurs which gradually merges into unweathered rock with depth. The paper summarizes the predictions of the elasto-plastic movement of the basement boundaries due to the excavation and the recompression of the bottom of the excavation due to the tower block loading. A finite element method is used to predict the movements of four alternative methods of excavation support. The non-linear stress-strain properties of the weathered lava are used throughout. The usefulness of the finite element method of analysis for excavation and foundation design is shown. The soil-structure interaction is highlighted by the calculations, as well as the direct design applications for the building that follow from the results.
The lateral resistance to wheel loads of a 1,065 guage railway track consisting of 48 kg/m SATS rails, Pandrol lastenings and Type P-2 prestressed concrete sleepers on standard SATS ballast was determined in the laboratory. The axle load, degree of ballast compaction and rail temperature were the parameters which were varied. As concluded by earlier investigators the axle load and ballast compaction showed signilicant influences on the lateral resistance whereas the temperature effect was negligible. At standard tamped density the well-known Prud'homme formula conservatively predicted the lateral resistance per axle as H = 10 x axle load/3 kN.