Mexico Subways?

Question

I understand that Mexico city is built on a filled in lake, how did they build the subways?

Answer 1

That is true for a good deal of the city, but of course not ALL of the city -- it has extended well beyond the limits of what used to be the lake and the metro system covers all regions of the city. Also, the lake dried up MANY years ago, so our soil isn't firm as a consequence of this but we don't have a lake lying 200 meters below the ground.... it's just soil and some of the stations have been built REALLY DEEP under the ground level. So we're not drowning when traveling through the subway or something...

Answer 2

The subway stations have a constrution reinforcement specially for the type of land .

Answer 3

Much of the "subway" system is lite rail above ground including the stations.

They built a tunnel under the English Channel so I assume building in wet ground is not impossible