I have a B1B2 visa.

It may be possible because civil eng is one of the fields in more demand, if you have five years of experience doing civ eng since graduation and (important) you actually want to work in that field. If you don't have the five years then try again when you do :-)

You will will need to find an employer who actually wants you, and wants you to work under supervision in your field (civ eng) and that will depend greatly on which state the employer is in.
Even if you find an employer you will still need to get your degree evaluated for equivalency (really that it is genuine and from a respectable Univ), several outfits are properly qualified to do this, for example WES www.wes.org WES is not the only outfit, but beware scams.
The employer will need to help you apply for Second preference and "Labor Certification" and file an immigrant petition. https://travel.state.gov/content/travel … html#first
All of which takes time and there is lots of competition. However there are places where civ engs are unkeen to work (bad crime, bad remoteness, bad weather) and so the employer will be delighted to have you and you have to research all that.
Once you have an employer on your side and the employer knows how to hire a decent immigration attorney, then you are away and taking the EIT (Engineer in Training) exam before you know it.

As I'm sure you are already aware, from an immigration officer's point of view there is a world of difference between "doing business" and "performing work". Even though a layman might be very hard pushed to tell the difference and there is no bright line separating the two.