system
Given the following post, respond as if you're commenting on Reddit:
human
[Multiple Universes] How do giant citys in futuristic settings deal with earthquakes?

For example, the world of blade-runner or any cyberpunk-esque city. Many discuss how when they couldn't expand out anymore, they began to build up. With the new being built on top of the old. Wouldn't this mean that the neglected undercity would be prone to structural failure? What if Coruscant had an earth quake?

To parahphrase on the sheer verticality of these cities, a companion in KOTOR 2 says: "Be careful where you walk in Nar-Shadaa, or you'll fall for hours."
gpt
Modern earthquake proof buildings are usually designed to sway during an earthquake, which disperses the energy. Some can move several meters, and the amount of movement is usually based the power of the earthquake. A huge earthquake hit Tokyo a few years back, and exactly zero buildings fell down. 

In sci-fi versions of Earth, this technology is integrated directly into the foundation of the mega-city itself. 

For planets like Coruscant, the planet's heavy terraforming has completely eliminated earthquakes. (Which are caused by the molten/liquid core)