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Buildings in some of the world’s major cities are sinking due to a “silent hazard” of climate change, warns a new study.
Researchers found the ground is deforming beneath our feet and many apartment and office blocks were not designed to handle it.
Buildings in older cities are most at risk, said scientists who added: “You don’t need to live in Venice to live in a city that is sinking.”
The American study is the first to quantify the effects of subsurface climate change on civil infrastructure.
As the ground heats up, it also deforms. The phenomenon causes building foundations and the surrounding ground to move excessively – due to expansions and contractions – and even crack, which ultimately affects a structure’s long-term operational performance and durability.
The research team also found that previous building damage may have been caused by such rising temperatures.
He explained that in many urban areas around the world heat continuously diffuses from buildings and underground transportation, causing the ground to warm at an “alarming” rate.
Previous studies have found that the shallow subsurface beneath cities warms by 0.1 to 2.5 degrees Celsius per decade.
But, until now, the effect of underground climate change on civil infrastructure has remained unstudied and little understood.
Loria said: “If you think about basements, parking garages, tunnels and trains, all of these facilities continuously emit heat.
His team have installed a wireless network of more than 150 temperature sensors across Chicago – both above and below ground, including in building basements, subway tunnels and underground parking garages.
For comparison, the team also buried sensors in Grant Park, a green space located along Lake Michigan, away from buildings and underground transportation systems.
Data from the network indicated that underground temperatures beneath the city are often 10 degrees warmer than temperatures beneath Grant Park.
Loria said air temperatures in underground structures can be up to 25 degrees higher compared to the undisturbed ground temperature.
After collecting temperature figure for three years, Loria built a 3D computer model to simulate how ground temperatures evolved from 1951 – the year Chicago completed its subway tunnels – to today.
He found values consistent to those measured in the field and used the simulation to predict how temperatures will evolve until the year 2051.
The team also modeled how ground deforms in response to increasing temperatures.
The simulations showed that warmer temperatures can cause the ground to swell and expand upward by as much as 12 millimeters (0.47 inches).
Although that seems subtle and is imperceptible to humans, Loria said the variation is more than many building components and foundation systems can handle without compromising their operational requirements.
Produced in association with SWNS Talker
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