Sandcastle engineering – a geotechnical engineer explains how water, air and sand create solid structures

There's a lot of science behind the natural forces that let this guy work his magic at the beach. Victoria Pickering/Flickr, CC BY-NC-ND

If you want to understand why some sandcastles are tall and have intricate structures while others are nearly shapeless lumps of sand, it helps to have a background in geotechnical engineering.

As a geotechnical engineering educator myself, I use sandcastles in the classroom to explain how interactions of soil, water and air make it possible to rebuild landscapes after mining metals critical to the energy transition.