TWINGEO: ARTICLE
PLEX.EARTH: TAKING THE GUESSWORK OUT OF CIVIL DESIGN BY LAMBROS KALIAKATSOS AND LAURA GARCIA
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f you are reading this article, odds are you’re a civil engineer, land surveyor, architect, or a designer, and it’s also a good bet that you’ve been spending quite a lot of your time redoing some work. Don’t feel bad; “Rework” has been a plague for all engineering projects, all around the globe, from the very beginning of civilization! Numerous studies estimate the average cost of rework on civil engineering projects to be higher than 5%, occasionally exceed-
ing 15% and some report about project reworking surpassing 30%. As a civil engineer I was the CAD manager and responsible for the design of the general layout on many sanitary landfill projects. Rework was some kind of a habit, since customers, contractors or other stakeholders were asking for changes regularly. It was just the regular routine. But one project forever changed the way I was seeing my job, and my tolerance of rework: A construction site had been installed and the first drillings started when we realized that the terrain in the northwestern part was substantially different than what we had in mind and designed for. Not surprisingly it was a steep area covered with dense vegetation and difficult to approach. I’m pretty confident the survey we had received for that part was the result of guesswork, which meant that our work was also a product of fantasy. There was no option: we had to redesign based on the actual terrain, which affected almost the entire facility. We wasted four months, but the numbers still shocked us: in a $6 million project, redesigning had cost us more than $600,000. More than 10%. Wasted.
The area of the landfill site where the topographic data was out of reality. Redesigning cost us more than $600,000 (10% of the total budget), and 4 months of delay. I keep this image as a reminder!
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