GZA GeoEnvironmental Inc. is a soils and foundations specialty consultant with 28 offices throughout the U.S., including one in Center City, Philadelphia. Founded in 1964, the employee-owned firm today offers geotechnical, environmental, water, ecological and construction management services to a wide variety of private and public clients.
One of my first jobs as a young geotechnical engineer was to provide foundation recommendations for a multistory building. As a geotechnical engineer, you investigate subsurfaces and provide architects and structural engineers with recommendations for the type of foundation they should use to support their building.
The architect for one of the multistory buildings I was working on, one time, had mentioned to me that the preliminary concept for the building was a pile-supported foundation, which is where pipes or concrete that are anywhere from 30 to 100 feet long are driven into the ground. This job involved a 40- or 50-foot pile foundation. It was going to be sitting on bedrock, so they would be able to put some heavier loads on the pipe piles.
I did the subsurface investigation, proceeded forward with the foundation analysis, and was probably about three-quarters of the way through the work when I began discussing the job with some other engineers. That’s when one of them asked if I had also considered a shallow spread foundation ... which I hadn’t. With shallow spread foundations, you excavate about three or four feet down and use concrete and some reinforcement steel. They’re a lot cheaper and less time-consuming than deep foundations. This building’s foundation could still be built on that, he said.
I hadn’t even thought about that. So I went back to the architect, found that it was within their parameters, and they ended up going with the shallow spread foundation. It saved the owner many times our design fee.
Don’t be afraid to ask questions.
That was kind of an “aha" moment for me because it really showed the importance of not proceeding on blindly. Really, the lesson here is: Don’t be afraid to ask questions.
Of course, there are things people expect us to know. As a geotechnical engineer, I don’t think it would be good to ask someone what they meant by “shale foundation” or “deep foundation,” because that’s something you really should know. But questions like “have you considered both the shale and the deep foundation?” and “what kind of budget do you have?” aren’t stupid questions. Those are the questions that will help you figure out what the architects are targeting.
Young engineers often shy away from this because they’re afraid they won’t look smart enough. But it’s really important that they communicate and understand all the design parameters before locking into something. Pretty much any time we have a problem at GZA today, lack of communication is usually what started it. So we tell people “if you’re out in the field, and you see something that doesn’t look right, bring it up right then. Don’t wait until you get back to the office, because it might be too late by then.” It’s much easier to fix a problem early on than when it’s fully completed.
Photo courtesy of GZA GeoEnvironmental Inc.