Building a pier, hot-dip galvanized or acid-proof??

[MathiasS]

Thank you very much for the pictures, I got a lesson in construction as a bonus!

Yes, I hope you benefit from them - this is a well-established way to build a pile bridge and not something we've concocted ourselves. Building with bearers and floor joists in this way has many advantages. The decking ends up in the right direction, you become completely independent of the position of the posts, it's easy to build an overhang, so the posts aren't visible or in the way, etc., etc.