Technically not civil engineering but similarly enough in the home-reno space. You can knock down a retaining wall relatively willy-nilly but a load-bearing wall needs a replacement thought out ahead of time.

So extended to concepts it always seemed a natural fit. I think where I picked it up in this regard was when used to describe Religion, in that you don't necessarily need the religions we have to "fill the god hole" but you need something of similar fortitude in order to maintain balance. The idea is that you can't just remove religion and then not replace it because it bears so much weight.