### id262791666 reasons retaining walls fail > All these types of retaining walls perform perfectly if designed correctly, but retaining walls do fail, and there are a few reasons why. One reason is just under designing for lateral earth pressure. It’s not intuitive how much force soil can apply to a wall, especially because the slope is often holding itself up during construction. Earth pressure behind a wall can build gradually such that failure doesn’t even start until many years later. Lots of retaining walls are built without any involvement from an engineer, and it's easy to underestimate the loads if you’re not familiar with soil mechanics. Most cities require that anything taller than around 4 feet or 1.5 meters be designed by a professional engineer. - [View Highlight](https://read.readwise.io/read/01fqy78n9zrpzzrm4saespc5rs) - [[Why Retaining Walls Collapse by Grady Hillhouse#id262791666 reasons retaining walls fail|View in Vault]] - [n] Useful for [[Civil Mage]] rules for building in the [[Nahrian Basin]] I'd love to see a #storystem/fic where [[Irella]] goes and investigates someone not doing this, see also [[engineers flatten building sites for long-term stability]]