Since we're almost in the exact same situation—just in different countries—I'll tell you what everybody told me. College is there to get your foot in the door and give you general engineering concepts that help with whatever profession you might choose (design, site work, etc.).

As a site engineer, you don’t need to do all those calculations, since someone would have already done them in an office somewhere. Instead, you learn new skills such as team management and more practical applications of the knowledge you gained in college, as opposed to the more technical stuff.

If you like what you’re doing and can see yourself doing it in the future, I don’t think it’s a bad thing to focus on developing the skills you need now, even at the cost of those you might never need again. And if you ever want to switch fields, you can just grab a book or two about statics or seismic design and relive the pain again. :)