Snakeskin inspires construction method for safer buildings
Image credit: Sergey Taran/Dreamstime
Constructing the foundations of buildings inspired by the scales on snakeskin could result in more resilient structures, according to researchers in Denmark and the US.
Despite human inventiveness and ingenuity, we still lag far behind the elegant and efficient solutions forged by nature over millions of years of evolution. This also applies to buildings, where animals and plants have developed extremely effective digging methods, for example, that are far more energy-efficient than modern tunnelling machines, and even self-repairing foundations that are unusually resistant to erosion and earthquakes.
Researchers from all over the world are therefore seeking inspiration from nature to develop the buildings of the future. Now, a joint study from Aarhus University in Denmark and University of California, Davis, in the US, has proposed constructing building foundations inspired by the scales on snakeskin.
“Previous studies have shown that surface geometry inspired by snakeskin can cause different shear strengths, depending on the load direction. We’ve taken this knowledge one step further in this research and investigated the interaction between different soil types and these snakeskin surfaces,” said Hans Henning Stutz, assistant professor, Department of Civil and Architectural Engineering at Aarhus University.
Builders usually make modern pile foundations by driving, drilling or pushing piles into the ground to achieve sufficient bearing capacity for a building. Today, builders usually prefabricate the piles with quadratic or circular cross-sections and a load-bearing capacity that is isotropic (identical in all shear directions) because of the mainly symmetrical, smooth profile of the surface.
However, in the study, the researchers experimented with asymmetric micro-structural features on the surface, resembling the scales along the underside of a snake. These so-called ventral scales are elongated in shape, relatively smooth and have cross-sections shaped like an elongated, right-angled triangle.
“By experimenting with ‘scales’ measuring 0.5mm in height and 20-60mm in length, we’ve achieved - in lab conditions - a significantly increased load-bearing capacity in the media we’ve examined: more specifically, different types of sand,” Stutz said. The results of the project also show that piles with this surface pattern give 25-50 per cent less resistance during installation compared with the pressure they can subsequently support.
According to Stutz, there is still a lot to learn from biology when optimising structures and durable foundations and he believes that future construction will find much more inspiration.
“Evolution has come up with some quite inspiring solutions during the ages and there’s a lot to be gained from a geotechnical perspective,” he said. “I’m convinced that in the future we’ll see major developments in bio-inspired and very effective solutions, especially in areas such as anchoring, tunnels and marine constructions.”
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