Those are inverted T-Walls. The "corrugated things" are the stems for each T-Wall block and they interact with the (future) backfill through friction to produce a resistance to the earth pressure that's on the back face of the panel. It's the same concept as other mechanically stabilized earth walls that use other anchor systems to interact with the backfill.What are those vertical corrugated things? I assume they're part of the foundation for the bike path, or are they part of the support for the retaining wall?
Where this really differs is that the stems get longer as you go up in elevation which is the opposite of conventional T-Walls, modular block walls, and gravity walls. The advantage of this system is that you can practically eliminate the need for excavation to install the wall because the panel stems are following the existing slope as they stack. If you're familiar with retaining wall design this also reduces the active wedge behind the wall.
With such a narrow corridor in some areas this a good system to use. The alternative wall type to use when you're so close to an existing right-of-way is soldier pile and lagging, which you also see all over this project corridor, but is more expensive.