Soledad Mashiri’s engineering research will help make homes safer for people living in earthquake-prone regions.
Earthquakes have caused an average of more than 20,000 deaths a year worldwide, of which more than 80 per cent occur in developing countries. ‘Earthquake-proof’ technologies exist, but many are priced beyond the reach of poor neighbourhoods and developing countries, which leaves the people living there vulnerable. A cost-effective solution may exist in one of the most obnoxious forms of garbage: old car tyres.
On 26 February 2010, Soledad Mashiri had her first meeting with her Master’s degree supervisors at the University of Wollongong. Two days later a magnitude-8.8 earthquake struck Chile in the early hours of the morning. The earthquake and subsequent tsunami claimed more than 500 lives.
“I remember that the first meeting with my supervisors … and two days later the city of Concepción in Chile—where I spent most of my childhood—was struck by a massive earthquake,” Soledad said.
“This earthquake made me realise that my research had a very important meaning and contributed to my passion for the topic. Thinking that thousands of lives could be saved in the future kept me well motivated during my journey.”
The topic that caught her eye was a project being led by Drs Neaz Sheikh and J S Vinod that involved using a mix of sand and rubber chips made from recycled tyres as a cushion around building foundations to reduce the impact of earthquakes on low-rise buildings.
“Not only is the sand-tyre mix more accessible to developing countries where resources and technology are not adequate for earthquake mitigation, it also has high potential for consuming a large amount of scrap tyres in an environmentally friendly way.”
There are billions of scrap tyres in landfill and storage worldwide, and they are tenacious waste—uncompressible, durable and non-biodegradable. These qualities, and their profusion make them cheap, which makes them an attractive candidate for new earthquake resistance technologies that can be employed by developing countries.
Engineers and architects need practical guidelines on how to prepare and deploy these sand-tyre mixes. Her research contribution will help bring the practical application of the sand-scrap-tyre mixtures a step closer.
“My investigation proposes a simple methodology of determining the optimum ratio of mixing sand and tyre chips in line with the design requirements for a particular project. It’s like a recipe—the right quantities of sand and tyre chips makes it easier to apply the technique during construction.”
It has been a decades-long journey for Chilean-born Soledad, now aged 51 and a mother of three, to complete her PhD. She was living in Sydney’s Western Suburbs and had spent the past few years working night shifts in a supermarket when she decided to look after unfinished business and return to her studies.
That journey began with a childhood fascination with engineering in Chile.
“I loved to spend time with my dad fixing toys, building up Meccano toy models and visiting construction sites,” she said. “My dad was in construction and built several important bridges in Chile, among other projects.”
Soledad studied civil engineering at the Universidad Técnica Federico Santa Maria (UTFSM) in the city of Valparaiso, graduating in 1991. The following year she enrolled in a Masters of Civil Engineering at UOW, where she would meet her husband and change her life course, leaving her Master’s partially complete.
The couple moved to Chile to work in the family construction business and returned to Australia in 1997 when her husband took up an offer to do his PhD at Monash University in Melbourne. That move was followed by several others in the next decade in pursuit of academic opportunities.
The family, now with three daughters, eventually settled in Western Sydney, close to where Soledad’s academic career had been put on hold.
After finishing her Masters with flying colours, her supervisors urged her to continue the research and apply for a PhD under the guidance of Drs Sheikh and Vinod. The thesis, now complete, is a long time coming for Soledad, but the true test of her work will be its contribution to building techniques around the world.
“I believe that every engineering project should have a distinct social benefit. We are responsible of our contributions to society and should consider the global benefit rather than individual or personal benefit.”