'Underground climate change' can damage building foundations, civil infrastructure

A phenomenon known as “underground climate change” can lead to damage of building foundations and civil infrastructure, according to a researcher at Northwestern University.

When the ground gets hotter, it can expand and contract, causing foundations to move and sometimes crack. The Northwestern study focused on Chicago, which has a predominately clay subsurface that can contract when heated.

The concern is not limited to the Windy City, though, as many other urban zones contain fine-grained soils that are vulnerable to such deformations. Cities are more likely than rural areas to feel the effects of underground climate change because construction materials trap heat that is transferred below ground. The research team found temperatures under the densely developed Chicago Loop were often 10 degrees Celsius warmer than those under Grant Park.

Underground climate change will not cause sudden failure like a building collapse, rather it is a slow process that degrades structures over the years. To counteract this trend, building teams can reduce the amount of heat entering the ground by installing thermal insulation.