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[BBC] Most modern structures are built to last 50 years or so, but ingenious ancient engineering has kept this watery city afloat for more than 1,600 years – using only wood.
As any local knows, Venice is an upside-down forest. The city, which turned 1604 years old on March 25, is built on the foundations of millions of short wooden piles, pounded in the ground with their tip facing downwards. These trees – larch, oak, alder, pine, spruce and elm of a length ranging between 3.5m (11.5ft) to less than 1m (3ft) – have been holding up stone palazzos and tall belltowers for centuries, in a true marvel of engineering leveraging the forces of physics and nature.
In most modern structures, reinforced concrete and steel do the work that this inverted forest has been doing for centuries. But despite their strength, few foundations today could last as long as Venice's. "Concrete or steel piles are designed [with a guarantee to last] 50 years today," says Alexander Puzrin, professor of geomechanics and geosystems engineering at the ETH university in Zurich, Switzerland. "Of course, they might last longer, but when we build houses and industrial structures, the standard is 50 years of life." |