Here is the full list of all 13 Bridge Project achievements.
Solved Bridge Farm # 8 using wood only
Create and share a custom map to the Steam Workshop
Solved all Briges Group #4
Solved all suspension bridges
Solved all game maps
Solved all Canyon's Bridges
Solved 32 bridges
Solved 24 bridges
Solved all Cities' Bridges
Solved all draw bridges
Solved 16 bridges
Solved all Farm's maps
Solved 8 different bridges