The civil engineering profession, together with other professions that stand in the gap for humanity, can take deep pride in that it is our professional and moral expectation and duty to do our work well, because we stand between the mountains and the plains, and though sometimes we are overcome, more often we are overcomers.
In the days following the magnitude 9,0 Tohoku earthquake which struck off the northeastern coast of Honshu, Japan, on 11 March this year (Figure 1; U.S.G.S. 2011), the world watched in awe as the extent of the destruction wrought by the strong ground motion and subsequent tsunami was revealed. It is estimated that more than 11 000 people lost their lives (Reuters 2011), with entire towns flattened and swept from the map. The region's infrastructure and industries sustained significant damage, the most publicised example being the nuclear energy sector. Yet, when the sheer magnitude of the quake is taken into account - it is the fifth largest quake yet recorded by modern instruments, and by far the largest in Japanese history (U.S.G.S. 2011; Rhea et al 2010; Utsu 1990) - it is surprising that the loss of life and damage to infrastructure was not significantly larger.
Recently I had the pleasure of dealing with a group of Young Professionals (YPs) from the World Federation of Engineering Organisations (WFEO). The committee is called Young Engineers / Future Leaders (YE / FL) and it is responsible for championing the cause of YPs and students within the engineering profession. The name of the committee says it all, and it got me thinking. Are YPs in South Africa aware of the role we need to play in the future of our society, and do we know how to become the leaders of tomorrow?
Esorfranki Geotechnical, together with earthworks specialist Zero Unlimited as the main contractor and demolition company Wreckers Dismantling, has completed the basement excavation and structural piling at 115 West Street - the new Alexander Forbes headquarters in Sandton, Johannesburg. This massive refurbishment project is being undertaken by Nedbank Corporate Property Finance on behalf of Zenprop Property Holdings (Pty) Ltd.
By and large, when geotechnical engineers get talking about their field of work, expressions such as 'challenging', 'exciting', 'fantastic', 'stimulating', 'passionate', and 'great fun' regularly crop up. With Alan Leslie Parrock, the level of enthusiasm reaches unrivalled heights. Lorraine Fourie spoke to Alan, the A of ARQ Consulting Engineers and the winner of SAICE's Geotechnical Gold Medal for 2010, about some of the outstanding moments in his career and discovers his exceptional zest for life. For this engineer work is fun, and the theatre of life is his playing field.
Geotechnical design in South Africa has traditionally been carried out using working stress design (WSD) with global safety factors. Since neither resistance nor working load is known with absolute certainty, a safety factor is required to ensure that the incidence of failure is either tolerable or improbable.
Since its launch in 2005, Google Earth has provided free public access to satellite and aerial photographs of the earth's surface. In addition to providing images from above, there are a number of features in Google Earth which are extremely useful when carrying out geotechnical investigations.
Internet access and usage in South Africa has seen incredible growth since it first arrived on our shores over two decades ago. Current demands placed on existing infrastructure has, however, necessitated the need for an improved network that is capable of processing and managing more data at both higher speeds and lower costs, while generally increasing the accessibility of the networks across the country.
It is a most disconcerting fact that certain soils have not 'read' the published theories. Several theories exist relating to the expansion of clays and to the prediction of swell pressure. Swell pressure is often defined as the vertical overburden pressure which will prevent the clay from expanding when it is wetted. The different methods used to measure swell pressure, however, give very different values.
Experience has shown that mechanically stabilised earth techniques find application in structures of great diversity. Design engineers now seem able to provide economic and aesthetically acceptable solutions for an increasing range of structures in order to meet specified technical, environmental and sustainability requirements. In the recent past the South African Reinforced Earth company (RESA) has been involved in a number of major projects where the size and nature of the projects demanded not only conformance with standard Reinforced Earth design and procedures, but also created positive advances in the company's administration, design techniques and method of supervision.
The Department of Civil Engineering at the University of Pretoria has recently been awarded a grant from the National Research Foundation (NRF) to acquire a geotechnical centrifuge. Geotechnical centrifuges are used to accelerate soil models to create a stress field in the model analogous to that occurring in the full-scale situation being modelled. At present there are approximately 110 geotechnical centrifuges around the world and only one in Africa, namely at Mansoura University in Egypt.
The demands of infrastructure development worldwide are one reason why we are faced with challenging engineering problems requiring competent solutions to reinforced soil structures (RSS). Maccaferri, which has more than a century of geotechnical solutions on record (firstly with mass gravity gabion walls, and secondly with reinforced soil structures) therefore developed custom software to suit all the requirements of their engineers around the world - Mac.St.A.R.S. (Maccaferri Stability Analysis of Reinforced Soils). This software was developed in the late 90s in collaboration with Studio Geotecnico Italiano and Autosoft. Mac.St.A.R.S. was validated against the current best software on the market before it was released for use.
As part of the deepening of the pit at Jwaneng diamond mine in Botswana, SRK was required to provide a detailed probabilistic stability analysis of the east slope to optimise the design of Cut 8, to ensure the integrity of the plant installations in its vicinity. The analysis was one aspect of a larger comprehensive design philosophy applied by Debswana and described in the paper by Tunono et al (2011) titled, "Geotechnical Design of Jwaneng Mine Cut 8".
The Geotechnical Division of SAICE held its Annual General Meeting on 25 November 2010. The AGM is a wonderful opportunity for SAICE's geotechnical family to get together and remember the successes of the previous year and look forward to the highlights of the coming year.