Alireza Gharib Blog

If you’ve ever gazed at the shoreline of Santos, Brazil, and felt like something was tugging at your inner eye level, you’re not alone. In fact, you’ve spotted one of the world’s most bizarre architectural phenomena.

Santos is an interesting contradiction—it’s a sunny coastal city with pristine beaches that also plays host to a bustling port. What draws the eye, however, is the skyline—it’s decidedly askew. This isn’t a Photoshop job or some avant-garde urban planning experiment, either. It’s a consequence of engineering hubris, poor planning, and geology just doing its thing.

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It’s easy to spot the lean on the buildings in Santos. Credit: janhamlet, CC BY-NC-SA 2.0

The Leaning Tower of Pisa is celebrated for being a building that somehow tilted over without collapsing. In Santos, though, that sort of thing barely raises an eyebrow. The city is dotted all over with buildings on the tilt. From 2004 to 2012, all 651 beachfront buildings were measured, and all were off-kilter to some degree. Some are just barely leaning over, maybe a couple of inches out of level. A more extreme example, like the Excelsior, measures 1.8 meters out of level. It’s a severe tilt that you can spot at an instant.

Santos didn’t set out to create its very own gallery of modern Leaning Towers. Most of the city’s lopsided skyscrapers were constructed in the 1950s and 1960s, during a period when Brazil’s building codes were more permissive.

Developers eager to cash in slapped together high-rise buildings with foundations only a few meters deep. This is perfectly valid when construction takes place directly on solid bedrock, but Santos sadly lacks such a convenient base. The ground is instead a bed of sand, seven meters deep, which sits upon a deeper bed of clay. Constructing the buildings with deep foundations down to the bedrock below would have avoided this problem, albeit at some expense. Instead, developers just pushed forward with the cheaper option.

Fast forward a few decades, and the problems are obvious. Over time, the towers weight tended to push out water from the clay below, leading to the buildings sinking somewhat, and often quite unevenly. The result is a skyline that looks like it’s leaning with the wind, with around 100 buildings visibly off-kilter to the naked eye. It’s a unique sight—and a rare one at that. Where else will you see modern skyscrapers looking like they’re about to fall right over?

The geology of Santos, combined with engineering decisions, lead to the problem. Credit: “Innovative techniques…”

Despite the lean, many of these buildings are still in use, most of them as residential housing. The buildings are regularly inspected and maintained, a sage decision given the ominous angles of lean. So far, there haven’t been any major catastrophies, so much as minor inconveniences. Problems with stuck doors and windows are common, and in many cases there’s an easily-detectable lean when walking around inside. Some owners choose to compensate by levelling their floor, though it’s usually still obvious there’s a problem whenever looking at the walls.

Over the years, there’s been talk of fixing the leaning buildings. Engineers have explored various means of jacking them back upright. Sadly, the cost of leveling even a single building is astronomical, and so far, only two have been corrected. Getting the buildings back into plumb involved huge hydraulic jacks, and the construction of new subfoundations able to properly support the building without further subsidence.  This cost was, at the very least, offset to some degree by the fact the value of the apartments in the buildings rose significantly after correction. Still, for the rest of the buildings in Santos, though, it’s pretty much lean or bust.

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