CSIR Coastal Engineering Expert Wins Esteemed JD Roberts Award
17 July 2009
The development of innovative methods for effective monitoring of harbour and coastal structures is one of the factors that came into play when Dave Phelp of the Council for Scientific and Industrial Research (CSIR) was selected as the 2009 recipient of the prestigious JD Roberts Award. These coastal engineering methods play a major role in ensuring the safety and integrity of coastal facilities. The winner was announced at a function held at Murray & Roberts on 16 July 2009.
Phelp's outstanding leadership in technology research and development is clear, as reflected in the successful realignment of the CSIR's physical modelling laboratory in Stellenbosch to become a world-class facility. This research facility plays a major role in enhancing port and coastal engineering capabilities and expertise in South Africa.
The annual JD Roberts Award is sponsored by Murray & Roberts and held in partnership with the CSIR. Instituted by Murray & Roberts in the late 1970s in remembrance of one of the group's founding fathers, Dr JD ‘Douglas' Roberts, the award recognises and promotes competitive and environmentally-sustainable solutions to human dilemmas and encourages scientific research into technology that will enhance the quality of life of all South Africans.
Douglas Roberts was a doyen of the construction industry in South Africa, well known for his entrepreneurial flair and passion for seeking and trying new techniques and ways of doing things. It is in this spirit that the JD Roberts award takes place annually, recognising talent and research within the CSIR.
Phelp has developed a novel aerial survey and analysis method that provides the required accuracy for monitoring the armouring of breakwaters and coastal structures. These structures are essential for the safety of the coast that they protect; they are progressively damaged during extreme storms. Most of the damage occurs near the water line, where access and visibility are complicated and even dangerous. Phelp's method allows accurate comparisons to determine the amount of damage in a precise way, while corresponding closely with the way damage is recorded in physical models.
Several methods were used in the past, such as conventional surveys or a crane-and-ball profiling method. These methods have severe limitations, are costly and lack sufficient accuracy.
With GPS positioning, a helicopter can hover at predetermined positions above the breakwater. Digital photographs are taken from the above-water armouring along the structure at low tide. Using fixed marks on the breakwater or structure, the photographs can be adjusted in scale and angle by image processing software, to match exactly the previous set of photographs. The differences between the old and new images can be quantified in the form of damage or displacements.
This method was originally perfected in small-scale modelling of breakwaters in the CSIR's hydraulics laboratory in Stellenbosch. A series of fixed cameras is used rather than model helicopters to allow accurate assessment of damage of the structures as a function of the wave conditions. Digital image technology has been extended to accurately monitor the movement of moored ships and even the measurement of very small waves in the physical model.
Phelp has trained a number of researchers to undertake the new aerial surveys and perform the image processing and analysis for both model and prototype structures. All breakwaters and most coastal structures in South Africa are now being monitored by Phelp and his team, especially after severe storm events, such as those along the KwaZulu-Natal coast in 2007, and the Eastern Cape in 2008.
Under the scrutiny of international experts, this technology was recently used successfully for the model testing of a major new port, Khalifa, in Abu Dhabi. The model monitoring system has been adopted by a number of world-class laboratories, including at the National Research Council of Canada in Ottawa.
Phelp has been invited to collaborate with the coastal engineering section of the American Society of Civil Engineering, and to compile a manual on breakwater monitoring.
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