Well, that blows. I am one of 5 women to work in my department (coincidentally, I'm a bridge engineer, so I can relate
) but our company is phenomenal. I NEVER feel looked down upon because I have boobs. Of course OUTSIDE of the office it isn't always so awesome (creepy construction guys WILL hit on you, consider yourself warned, lol!), but I never feel like a second clas citizen at work. I have other female friends in the industry at other companies, and I know that this isn't always the case, so I def feel your pain.
Although part of it might because I'm a tomboy and can be more crass than half my coworkers
When we go out to lunch, I have a beer just like the rest of them. I dunno, I guess that's just me being a tomboy though.