Civil Engineer in South Africa - Volume 21, Issue 2, 1979
Volume 21, Issue 2, 1979
Author T.P.C. Van RobbroeckSource: Civil Engineer in South Africa 21, pp 29 –35 (1979)More Less
The paper shows that many of the centres of high water consumption in South Africa are situated in areas where available water resources are scanty. Details are given of several schemes which supplement local resources by transferring supplies on a large scale from well-watered areas. As the continued growth in the Republic will depend on further inter-basin transfers a number of projects now being planned are described.
Hierdie referaat toon dat baie van die sentrums met 'n hoë waterverbruik in Suid-Afrika geleë is in gebiede waar die beskikbare waterbronne karig is. Besonderhede word verstrek van verskeie skemas wat plaaslike bronne aanvul deur die oorplasing van voorrade op groot skaal vanaf waterryke gebiede. Aangesien die voortgesette ontwikkeling in die Republiek sal afhang van verdere oorplasings tussen stroomgebiede word 'n aantal projekte beskryf wat tans beplan word.
Source: Civil Engineer in South Africa 21, pp 37 –39 (1979)More Less
The position and height of rectangular platforms for new houses in undulating terrain are to be determined. Cut must be accommodated on the stand. Slopes from the edge of platform or fill must be within given bounds and must meet the natural surface within the boundaries of the stand. The objective is to minimize cut. The problem can be formulated as a separable mathematical programming problem.
A quadratic function of the two horizontal coordinates approximates height adequately in this particular case. Such a function is fitted for each stand and exploited to find certain line integrals, potential fills, etc analytically. The constraints are so severe that there is little opportunity for optimization and the problem reduces to one of satisficing.
Inputs consist of a list of (x, y, z) points generated by stereoplotter, exact (x, y) corner points of stands and for each stand the seven numbers which identify the (x, y, z) points covering the stand. Output specifies positions and heights of platforms as well as meeting points with the natural surface. Cut, fill and excess figures are also produced per stand and in total, while a computer plot of the township shows all information needed for the execution of the groundworks.
This new application of computers in the field of civil engineering proved to be a time and money saver in the best tradition of automation.
Author D. HopkinsSource: Civil Engineer in South Africa 21, pp 41 –43 (1979)More Less
When considering flow in pipe systems, modern textbooks in common use apply cumbersome methods of solution as well as one of trial and error when the discharge in branch pipes, total head and pressure drop along a main have to be computed from a given total discharge and known pipe characteristics. The object of this article is to introduce a novel and simple method for the direct and explicit solution of problems associated with series, parallel and series-parallel pipe systems as dealt with in straightforward design as well as in hydraulic engineering courses at universities.
By die behandeling van vloei in pypsisteme gebruik moderne teksboeke lomp en probeer-en-trefmetodes vir die bepaling van sowel die deurstroming in pypvertakkings as die totale druk en die drukverliese oor die sisteem wanneer die totale deurstroming en die pypeienskappe bekend is. Die doel van hierdie artikel is om 'n netjiese en eenvoudige metode voor te stel vir die direkte oplossing van probleme rakende serie-, parallel- en serie-parallel gekoppelde pypsisteme wat eie is aan sowel eenvoudige ontwerp as kursusse in hidrouliese ingenieurswese aan universiteite.