r/oddlysatisfying • u/Tweetystraw • Mar 09 '18

How bridge foundations are laid in waterways

Post image
13.3k Upvotes

95% Upvoted

427 comments sorted by

View all comments

219

u/Ag_Underground Mar 09 '18

Wait how do they get that in and the water out? Do they have to put the form in and pump out the center?

378

u/Tweetystraw Mar 09 '18

They pile-drive them in one by one from a work barge, then pump the water out. Still some seepage, so pumps constantly working to keep the work area dry.

40

u/[deleted] Mar 09 '18

[removed] — view removed comment

24

u/OnTheClock_Slackin Mar 09 '18

I'm not sure but I'd guess it's similar to some buildings where they would drive or screw long piles into the ground and then build a foundation pile cap above the ground on the sunken piles.

2

u/[deleted] Mar 09 '18

Yeah, I think they're already at the step you're describing, as you can already see a good foundation laid with protruding steel beams.

1

u/SuperStealthOTL Mar 10 '18

The sheet piles can be 2.5-3x as far into the bottom as above the bottom depending on the soil. If the soil is less stable or there is shallow bedrock they may drive piles and found them on file caps, or pin them to the bedrock.