In 2010 Stanford University, one of the twenty most prestigious universities in the world, established a Heroes Programme to recognise the groundbreaking achievements of engineers, and the profound effect engineering has on people's everyday lives.
In its biggest project in Ghana to date, Frankipile Ghana, a division of Esorfranki Geotechnical, is on schedule for the June 2013 completion of the design and implementation of temporary works required for the construction of the off shore rock groynes for the Ada Coastal Protection Works. The temporary works for the entire project will involve approximately 2.5 linear km of jetties and 1.5 linear km of sheet piles.
In many ways the 2012 recipient of the Gold Medal awarded by SAICE's Geotechnical Division personifies the essential geotechnical engineer. Says Gavin Wardle: "We love every moment of our work, but we don't do it on our own, we do it in collaboration with others and it is the joint effort that makes the outcome so rewarding and successful." That is why, apart from feeling "honoured that his body of work has been regarded as contributing to geotechnical engineering in South Africa", he cannot but pay tribute to colleagues past and present - several of whom are previous Gold Medal recipients - and mentors who have contributed to his development.
Various wind farms are now under consideration by the South African power authorities, as part of the renewable energy drive to lower the reliance on coal. This article describes the geotechnical aspects of one at present under construction in the Eastern Cape.
This article discusses the increased use and applicability of the Continuous Surface Wave (CSW) test by using three recently completed projects as examples - a major bridge over the Jukskei River in Gauteng, extensions to the engineering building at Stellenbosch University, and the rehabilitation of a dolomite subsidence on the R21 freeway. These examples prove the value of the test in supplementing information on ground conditions gathered from other investigative methods, in deriving design parameters where no other test method is possible, and as a tool used for quality assurance purposes on a major construction project. In one of the examples significant cost savings of over R2 million were achieved through well-executed geotechnical investigations where particular reliance was placed on the CSW test.
The purpose of this study was to evaluate the benefits of carrying out slope stability analysis using finite elements (FE) in addition to the more common limit-equilibrium (LE) method. Several slope stability projects were drawn from our archives for this exercise, although for the sake of brevity, the results of only three are presented herein.
Aurecon Ground Engineering Cape Town is currently assisting Aurecon Ground Engineering Christchurch New Zealand with individual geotechnical reports for damaged homes as a result of the recent sequence of earthquakes and aftershocks that have affected the South Island's largest city (population about 450 000). These reports are part of the insurance process. The author visited the city in January 2013 to gain a better understanding of the Christchurch geology and geomorphology in terms of the inputs into the geotechnical reports, and at the same time to observe first-hand the effects of the earthquakes on the city as a whole. South Africans are not commonly directly exposed to ground shaking and the devastating effects thereof, apart from low-magnitude ground shakes related to mine-induced seismicity from time to time. The widespread accessibility of various forms of media these days does of course give us an inkling of the effects of such disasters.
This article showcases Aurecon's involvement in the rehabilitation of a section of the N14 north of Carletonville following the occurrence of a number of sinkholes on the road shoulder that resulted in complete road closure. Three sinkholes formed on the road shoulder at some time between late December 2007 and early January 2008. Two sinkholes (each about 10 m in diameter) formed on either side of a box culvert (see Figure 1), and another on the opposite side of the road (about 4 m in diameter). A 15 km section of the road had to be closed and traffic was diverted along existing roads. Sinkhole rehabilitation and upgrade of the closed section of the N14 is being undertaken under Aurecon's supervision at present. At the time of writing, the rehabilitation work described in this article was in its final stages.
The road is currently under the jurisdiction of the Gauteng Department of Roads and Transport, with the South African Roads Agency (SANRAL) acting as implementing agent on the project.
Located approximately 50 km southwest of Kenya's principal port city, Mombasa, lies the Kwale Mineral Sands Project. The project comprises the near-surface extraction of numerous minerals, and an associated processing plant. The mine will produce titanium, ilminite, zircon and rutile over its expected 13-year lifetime.
The Kamoa Project is a newly discovered, very large stratiform copper deposit with adjacent prospective exploration areas within the Central African Copper Belt, approximately 25 kilometres west of Kolwezi and about 270 kilometres northwest of Lubumbashi in the DRC. Golder Associates Africa (Pty) Ltd was appointed by African Minerals Barbados Limited, a subsidiary of Ivanplats Limited, to provide engineering and environmental consulting services for the project, which included a wide range of preliminary geotechnical engineering studies. A summary of these studies is presented herein.
The shortage of borrow sources for granular material, combined with the limited availability of funds for rehabilitation projects, is generating more opportunities for innovative engineering in order to achieve cost-effective solutions. Since the introduction of geosynthetics, governments, consultants and contractors have been assisted to deliver projects to stakeholders. Geosynthetics are now considered necessary and indispensable for a cost-effective solution in multiple functions, such as reinforcement, separation, filtration, drainage, barriers, erosion control, containment and protection (ISO 10318:2006: Geosynthetics: Terms and Definitions).
The successful installation and commissioning of a geotechnical centrifuge in the laboratories of the Department of Civil Engineering at the University of Pretoria was reported in the April 2012 edition of SAICE's magazine (Civil Engineering April 2012). The centrifuge was installed in a newly created laboratory converted from a lecture hall in the basement of the civil engineering laboratories on the university's main campus. The new centrifuge laboratory was opened by the Vice Chancellor and Principal of the university, Prof Cheryl de la Rey, on 13 June 2012. Now, less than one year later, more than 130 centrifuge tests have been registered in the centrifuge log book. It is intended to use this facility to significantly increase the research output of the Department of Civil Engineering, not only in the field of geotechnical engineering, but also in other disciplines. This article presents an overview of the geotechnical group at the University of Pretoria and its activities.
The JE Jennings Award is presented to a member of the SAICE Geotechnical Division who is the author of a meritorious publication relevant to geotechnical engineering in South Africa, published during the previous year.
Working as a senior contracts manager in the 1990s, Boyd Cousins realised that South Africa was relatively isolated from the world in terms of piling equipment. Existing equipment was based on old-style mechanical designs and know-how, some of it 30 years old. Although the hydraulic era was coming into its own, one had to rely mainly on visits to overseas companies to get ideas or see what rigs were being developed.
In a continued effort to stay abreast of new technology in geotechnical investigations and exploration drilling, Geomechanics recently took delivery of its new R7 million track-mounted Sonic 450-24 drill rig.
One of the exciting, but challenging projects that Diabor (which in 2013 is celebrating its 30th year in operation) was involved with during 2012 was a geotechnical investigation of the Hazelmere Dam wall near Durban in KwaZulu-Natal. The main purpose of the investigation was to establish whether the dam wall could be extended both in height and width to increase holding capacity. Diabor was contracted to drill core samples from within the dam wall itself to establish the feasibility of such a venture.
Mponeng mine, formerly Western Deep Levels South Shaft, situated in Carltonville, western Gauteng, is one of the richest gold mines in the world and so deep that a trip from the surface down to the bottom (reaching 3 400 m) takes over an hour. In 2012, Kaytech's RockGrid PC was installed at Mponeng mine when high-tensile, geosynthetic polyester grids were required for reinforcement of a newly constructed concrete retaining block wall.
ECSA (Engineering Council of South Africa) has prepared five case studies arising from the contravention of ECSA's Rules of Conduct for Registered Persons. These case studies are offered to the engineering fraternity as advisory notes to minimise the risk of recurrence. Civil Engineering will be publishing these case studies over five editions - herewith the second of these case studies. The first case study in the series appeared in the March 2013 edition of Civil Engineering (page 75).