1) This isn't a homework help forum. <end scolding>
2) Since it's of potential interest to people, the math involved in structural engineering hits either simple algebra and geometry or it plunges deep into the terrifying depths of calculus and differential equations and whatnot... Hard to find a happy medium... Most of the things you talk about are pretty linear.
Lots of trig, though. Check out vibration, which we use a lot when we figure out what sorts of forces rotating machinery (engines for factories, some medical equipment, etc) applies to structures, how people jumping up and down in stadiums and walkways vibrate the things they're jumping on, and how earthquakes affect structures. Vibration - Wikipedia, the free encyclopedia
Wikipedia is your friend, and starts out fairly simply.
Good luck with your project!