Standard penetration test

Okay kiddo, so imagine if we had to build a house on the ground but we didn't know how strong the ground was. Would that be safe?

No, it wouldn't be safe at all. So, to make sure the ground is strong enough to hold up a house, we do something called a standard penetration test.

First, we take a long rod that looks like a straw and stick it into the ground. We drop a heavy weight on top of the rod and count how many times it takes for the rod to go down a certain distance.

This tells us how hard or soft the ground is. If the rod goes down easily, the ground might be too soft and we need to add more support. If the rod takes a lot of hits to go down, the ground is strong and we can safely build on it.

So basically, the standard penetration test helps us know how strong the ground is before we start building something on it. Pretty cool, right?