It seems like it would be prudent to have a bulkhead to confine flooding to something less than the entire new tunnel section while tunneling under the river. This type of construction flooding failure while not common, happens.
I read reports that the tunnel boring machine struck a Sewer line, which is what was flooding the tunnel. However I don't know that's true, and it seems information isn't easy to come by for this. either way it is a big mess
I'm not surprised. When I was there visiting the university, the people I was dealing with described San Paulo as the largest 'unplanned' city in the world, and I believe it. You're lucky to see two streets running parallel for more then a couple of blocks, if you can even call them blocks.
Considering that I was there during their Winter, the weather was great:
July 2015 (Sony NEX-3N)
July 2015 (Sony NEX-3N)
And the municipal market is one of the largest in the world:
July 2015 (Sony NEX-3N)
Where you can buy anything, including Piranha:
July 2015 (Sony NEX-3N)
But this was my lunch, along with a nice cold glass of beer:
Not sure what they called it, but it was good. ;-)
The people who took us to the market said that the shop where we bought them, that they were famous for their sandwiches, and from the looks of the line queuing up at their counter, I'd say they were right:
https://playcrazygame.com/2022/02/02/tatuzao-is-flooded-and-trapped-in-a-tunnel-after-an-accident-at-the-construction-site-of-line-6-orange-of-the-sao-paulo-metro-parts-will-be-replaced-sao-paulo/[/URL]]What is known is that the armadillo was heading south, towards the Tietê River, between the future Santa Marina and São Joaquim stations, and was about 3 meters below the level of the sewage pipe that broke and flooded the work, next to the ventilation shaft.
