The fundamental principles of a new approximate method of analysis for unbraced rigid frames are presented. The method makes use of a multi-curve interaction principle placing the failure load on the one hand and a load related to the elastic buckling load on the other hand. The failure curves between those extreme values are empirical. In this study they have been tested against 19 steel frame structures from previous research and 11 model frames specifically designed for the purpose of this investigation. In general, a better correlation with exact solutions was recorded than could be obtained from existing similar interaction techniques. Considering the simple application of the procedure, notably if the required elastic analysis components are further approximated, the method could become a useful tool for the engineer when designing sway frames.
Computer simulation of hydrological processes provides engineers and hydrologists with a reliable technique for the assessment of stormwater runoff. Many hydrological simulation models developed thus far are however main-frame computer orientated and, with the current popularity of micro-computers, a need for a micro-computer compatible hydrological simulation model clearly exists. This paper presents the theory and development of WITWAT, an urban drainage hydrological simulation model with built-in design and analysis features and based on South African hydrology. The model is suitable for application on HewlettPackard 85, 86, 87 and 9816 micro-computers.
The paper descriptionbed the geological conditions which were encountered in five different shallow tunnels constructed in the vicinity of Johannesburg. From these case studies an attempt was made to define geological factors, specific to each geographical formation, which could influence shallow tunnel construction in the area.