Building African Highways in More Ways Than One
Building highways has more than just a practical or economic value in sub-Saharan Africa. There's also a symbolic element to it in the cross-boundary co-operative efforts which are increasingly involved in Africa's growth and rebirth.
Modern technology - much of it sourced from South Africa - is being used in these enterprises where civil engineering skills of the highest order are increasingly in demand. As an example, locally developed computer design software is one of the cutting-edge instruments of infrastructural growth being used in the building of new roads, highways and bridges.
Let's look at two of our neighbour states - Tanzania and Botswana - where this clever civil engineering design technology is being harnessed for this purpose.
One South African engineering consultancy which is currently involved in detailed survey and design work for two new highways in Tanzania and Botswana is Kwezi V3 Engineers. One project is a 98m-long road linking the towns of Mingoyo and Mbwemkulu in eastern Tanzania; the other is a 32km-long highway between Mahalapye and Kalamare in Botswana.
Among the roads design software being used for the projects is CIVIL DESIGNER. Its SURVEY & TERRAIN and ROADS modules, which provide interactive earthworks design and calculations, have been applied in the preliminary design work on the two highways.
"It is one of our most frequently used - and most useful - road design tools," says du Bruyn Jonker of Kwezi V3.
du Bruyn Jonker finds the software particularly user-friendly in doing surveys and obtaining and plotting data about terrain and other factors and potential problem areas which he has to take into account - for example, the position of geographical features, natural obstacles such as trees, or man-made obstructions such as electricity or telephone lines. Typical problems faced by the civil engineer.
Jonker talks enthusiastically about the features of the Survey & Terrain module - especially the variety and ease in creating a terrace. Hearing him talk about it sounds more like a challenging computer game - but a game that you win at - than a serious engineering tool.
"If you don't like what you've drawn, you can easily change the layout, or just drag it across to another position on the site," he says. "It really is simple. Once you have completed the design, you just merge your terrace with the underlying grounds profile to create a final site model."
From the Survey & Terrain module, the design work moves to the comprehensive ROADS module, which incorporates interactive embankment design and calculations.
As an example of the software's flexibility and ease-of use, on one of the highways which Kwezi V3 has been working, the client had requested three separate and distinctly different road designs to cater for three different traffic speeds.
Different horizontal curves and gradients and other design criteria and parameters were involved in the three separate speed designs. For example, a higher-speed design naturally involved more gradual curves; a lower speed conversely allowed for sharper curves. All this and other criteria had to be factored into each separate design. It proved a simple task for the system - according to Jonker, CIVIL DESIGNER made possible the design of three separate roads in not much more time than it takes to design one road.