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Finding solutions to large and detailed problems in the area of infrastructure engineering by combining his knowledge of a variety of fields is what excites Dr James Maina. Recently promoted to a chief researcher at the CSIR - the highest ranking within the CSIR's research career ladder - Maina is also research group leader for CSIR transport infrastructure engineering.
His expertise in numerical modelling, characterisation of mechanical properties of materials, contact stresses between tyres and road surfaces, field testing and the use of high performance computing as a tool enables Maina to identify primary responses (displacements, stresses, and strains) anywhere within the pavement structure. Using this information, Maina and his team can then predict how roads will perform over a period of time. This information enables road owners to do proper rehabilitation and maintenance planning, taking into consideration options available.
Research projects that Maina currently leads at CSIR Built Environment include:
- Improving the ability to model the complex, non-uniform stress distribution of the contact path between tyres and pavements
- The improved modelling of geometric non-linearity in pavement systems
- The relationship between stiffness of pavement materials using different field and laboratory testing methods
- Documenting material testing, interpreting results, deriving design inputs and calibrating material models
- The development of a finite element package for pavement engineering applications
- Structural evaluation of layered structures based on wave propagation considering materials’ damping effect.
When the CSIR’s powerful C4 (CSIR Cluster Computing Centre) was launched in 2006, Maina and his research team were the first users of the facility. He says with the C4, research results can be expected in less than an hour as compared to a week.
Growing up in Tanzania, Maina loved maths at school and specialised in advanced maths, chemistry and physics in high school. On being the best final-year undergraduate student in civil engineering, he received an offer from the Massachusetts Institute of Technology (MIT) in the field of structural engineering. His passion was, however, pavement engineering and he took up the scholarships awarded to him by the Ministry of Sports, Culture and Education of Japan to study towards his MSc and PhD degrees in civil engineering at the Miyazaki University in Japan.
After a six-month crash course in Japanese, Maina could get by and acquainted himself more with the language so that he could converse fluently for research collaboration. “The Japanese people have an admirable outlook on life and an amazing work ethic of true dedication and long, productive hours. From a young age, the kids are taught to achieve the best you can regardless of the circumstances you are in,” he notes.
It was after his PhD studies that he started developing the GAMES (General Analysis for Multilayered Elastic Systems) computer program to assist the Japanese industry with evaluation of road and airport pavement structures. He finds it very rewarding that Japan now uses GAMES as a standard tool for determining displacements, stresses and strains on roads, and even at airports, including the second largest airport in Japan, the Tokyo International Airport. That airport carried 63 million passengers during 2008.
More locally, GAMES will be used as the analysis engine for the new South African Pavement Design Method (SAPDM). In addition, GAMES has also been used on two airports in Namibia and one in the Eastern Cape for determining the load bearing capacity of airport pavement structures. Several researchers in the USA, Europe and Australia also use the GAMES software and other packages into which GAMES has been incorporated.
Apart from GAMES, Maina is also developing software for pavement engineering application based on:
- Wave propagation analysis for both circular and non-circular impact as well as moving loads considering damping and visco-elastic material behaviour
- Finite element analysis for both static and dynamic loads considering linear and non-linear material behaviours
- Back-calculation (optimisation) analysis for evaluation of pavement structural condition.
Before joining the CSIR in 2005, Maina was a visiting scholar for two years at the Tokyo Denki University on a fellowship from the Japan Society for the Promotion of Science. He collaborated with private and public institutions on research relating to the improvement of pavement design and evaluation as well as performance prediction. Prior to that, Maina was chief research engineer at the research institute of NIPPO Co-operation, the biggest road construction company in Japan. There, his work included improving pavement construction practices as well as overall pavement structural and functional performance.
He is author or co-author of 20 journal publications, a book written in Japanese on pavement structural evaluation, 35 peer-reviewed conference papers and a number of invited conference papers and presentations.
In the Department of Civil Engineering at the Tshwane University of Technology in Pretoria, Maina is an external moderator for main and supplementary examinations in pavement technology, asphalt technology, construction materials and transport planning. His hope for the future is to mentor as many young CSIR colleagues and university students as possible in the field of transport infrastructure engineering.
Maina is a peer reviewer for a number of journals and conferences and also sits on numerous national and international (Japan and US) committees focusing on pavement engineering. These include the prestigious Transportation Research Board committee on flexible pavement design, which influences the trend of international pavement design and analysis.
Maina has a passion for sports and used to play soccer, basketball, table tennis and badminton, while also doing boxing and karate. On the home front, his wife does cognitive psychology relating to maths for small kids. Their two daughters, who are in primary school, were both born in Japan and had to expand their limited knowledge of English here in South Africa in the same way their dad had to quickly get fluent in Japanese. The Japanese approach to life has had a marked influence on the Maina family.
CSIR Strategic Communication and Stakeholder Relations:
Hilda van Rooyen, email: HvRooyen@csir.co.za
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