Sometimes buildings will have deep/long piles despite not being very high. Ie. Jinmao is 420m high, has 88 floors(excluding mechanicals), the length of the piles(not all of them but possibly the inner ones) reaches 83 meters at the foundation area of ~3.5k square meters. HOWEVER! Henglong Plaza in Shanghai, which is 'only' 288m and has foundation area of 3.2k square meters, has 81.5m piles :wtf:
Buildings in Shanghai and Suzhou need a lot of pilings because the cities sit on swampland and alluvial mud flows from the Yangtze river. You should see how big the pylons holding up bridges and highways are here. If they weren't that large, it would just fall through the ground like a toothpick in a stick of butter.
^^ The deep foundation piles are primarily to increase bearing capacity to support the whole building. Lateral deflection of the piles from liquefaction caused by earthquakes would be taken into account in the piling design. Usually by allowing for bending to a certain degree I believe.
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