Answer:
Yes, off course. However, with the math background that most architecture programs require, they probably wont be able to go too in depth in structural engineering. I'm an undergrad in civil eng. focusing on structures. Although structural engrs work closely with architects, the field itself is a very unique and technical and deals with alot of math, mechanics (statics, dynamics, mech. of materials, vibration,...)... Bottom line, anybody in the technical fields can study structural engr, but to BECOME a structural engineer, you most likely need a masters degree, PE license, as well as the SE license. AKA [lotsaa work] but cool stuff if you like it!