how dose the streets stay up if sewrs r below them?

Question

if sewers r below the streets how do they get the tar to stay up and straight???? why dosent it cave in!!!???

Answer 1

sewer pipes are made of thick 3-4" steel-reinforced concrete, and since it is a tube, its upper half distributes the pressure of the soil above like an arch, so the steady pressure of the dirt above never leads to cave-in. Many sewers are double-encased or have other structural supports around it, but a couple feet of dirt is simply not enough to cause a massive concrete tube to fail. Reinforced concrete is some tough stuff.

And no, steel beams do not keep a street up. Streets are built on a base of compacted soil and a gravel substrate, with asphault overlay. Again, the weight of the road material distributed over the dirt between it and the concrete piping that makes up the sewers is simply not enough to collapse it.

Answer 2

It's engineered that way. There are tons of support structures underneath the streets that you can see. They tunnel under the street and enclose it with cement and iron. It's like...how gophers tunnel underground except humans reinforce our tunnels so the streets can stay up. Next time you see a crew working in a man hole, ask them if you could peek down there or just ask them how it all works for a more in depth explanation.

Answer 3

Steel beams keep the streets in place. The tar is over the steel.