system
Given the following post, respond as if you're commenting on Reddit:
human
How do they build highways in loose sand?

My question is basically only what is in the title, I am trying to find out how paved roads in the desert are made. Normally, constructors lay down a subbase on the subgrade (which in this case is sand) then a base course over that and then the pavement. The subgrade is supposed to hold the whole weight of the road, how do they solve this in the desert?
gpt
Well it is possible because of a foundation technique known as pile foundation.

Piles are basically circular concrete columns that have been reinforced under the ground. There are two types of pile available

End bearing pile

Friction pile.

End bearing pile is the pile which transfers load to the strong soil. And friction pile distributes the load due to friction. In desert sand is available till a long depth so mainly friction pile is used.