Trimble Westminster Steel Case Study
Are you heading to Denver in October for the AGC BIMForum? Then you know the theme of this conference is prefabrication and modularization. It’s something we do instinctively when we see plans for a hospital or a high-rise apartment building – how can we apply Lean Construction principles to make these repeating floor plans easier to execute? After all, when we approach construction like an assembly line, we can introduce immense efficiencies and the project can take off.
At Trimble, we experienced this first-hand as we built our new Trimble Westminster campus, just up the road from the BIMForum in Denver. We were lucky to work with JE Dunn as the General Contractor, SCI was the Structural Engineer of Record, Zimmerman Metlas as the steel supplier/fabrication, and Dowco Consultants Ltd as the steel detailer. This top-notch team committed to the goal of utilizing Trimble’s own technology on the building – in fact, 29 different Trimble hardware, software, and construction solutions helped bring our project to life. This case study examines the steel used on the project.
Caption: Trimble’s new four-story, 125,000 sf office building in Westminster, Colorado, as depicted in SketchUp
The team for the Trimble Westminster Building utilized Tekla Structures and the Trimble Robotic Total Station to help with prefabrication efforts. Tekla Structures is critical from design through on-site quality control checks after concrete and steel installation.
As the team worked within the same Tekla Structures model, SCI was able to hand over the basis of the structural steel design and engineering to Zimmerman and Dowco, who were then able to add their specific details for the anchor bolts, steel embeds, knife plates, bolt patterns, welding notes, steel stair detailing, steel decking, and miscellaneous metals. The detailed native Tekla Structures model was then handed back to JE Dunn and SCI for In-model review in lot increments corresponding to a comprehensive fabrication, delivery and installation sequence. The structural steel shop drawing review procedure was reduced by approximately 33% when compared to the more antiquated paper or even .pdf document review process through the Lean and
IPD construction processes.
Employing Tekla Structures’ layout manager, JE Dunn Construction was able to produce concrete and anchor bolt points within the native model and export those points directly to their Trimble Robotic Total Station 633 with the Field Link Controller Tablet for 3D model viewing during layout. The precise methods of layout and
quality control ensured the anchor bolts were all set within 1/16” of the model
location and in relation to each other.
Caption: Watch this amazing video from Trimble's own Westminster Campus construction to see the column set in place with vertical plumb within 1/8 of true 90 degree vertical.
Tekla Structures and Tekla BIMSight was also utilized for constructability reviews and
production of concrete lift drawings which allowed for clash detection of the steel embeds with HAS (Headed Anchor Studs) against the fully detailed rebar and concrete formwork requirements. The Trimble RTS 633 and Trimble Field Link were also used to lay out grid lines on each column base and concrete elevator and stair cores as well as elevations shot in with Spectra Precision Lasers to guarantee the structure installation all conformed to the Tekla model. Quality control measures, including lift drawings produced within Tekla Structures, combined with the Trimble RTS layout, confirmed all anchor bolts and embeds were installed with 100% accuracy and structural RFIs were reduced by 50% to 67% when compared to traditionally delivered projects.
The highly accurate layout allowed the steel erection subcontractor, Total Welding Inc., to install each lot of steel columns and beams within 4.5 days, in lieu of the estimated two week duration originally scheduled. TWI was then able to complete all of the detailed steel work including bolting, decking and welding typically not completed until after full structural steel installation. The precise positioning of the stair cores and provided layout also allowed the early installation of the final steel stairways prior to any of the floor decking installation. The steel workers, MEP and concrete subcontractors were then able to access the upper levels without temporary stairways or ladders providing a safer and more efficient work environment, again reducing the overall schedule. All major structural steel installation and detailing was completed within the 10 week duration originally scheduled but also eliminated another four weeks of welding and bolting normally required over other trades while allowing the concrete decks to be completed.
Caption: JE Dunn layout foreman, Troy Hernandez, utilizing the Trimble Field Link and MT 1000 Active Prism to check pre-pour camber of steel beams
JE Dunn was also able to complete a great deal of quality control measures utilizing the Trimble RTS and importing the as-built points into the Tekla Structures model to help set steel columns, check concrete slab steel edge angles, pre and post-pour steel beam camber checks, and ensuring interior slab openings were within tolerances. Although pre and post-pour steel beam camber is not typically checked on most projects, JE Dunn found it very useful information to have for structural engineering verifications (once low and high areas in the concrete slab were found). Developing a consistent quality control program including pre and post-pour camber verification for each steel beam should be included in any future structural steel projects. The use of Tekla Structures and the Trimble Robotic Total Station with Trimble Field Link and the Trimble MT1000 Active Prism helped to provide 100% accurate installation of the structural steel and concrete and also allowed JE Dunn Construction to provide grid offsets on all of the upper levels for use by the other trades and complete the exterior and interior wall, window and door layout.
Be sure to check out our other prefab solutions, including the concrete case study for the Westminster project, a virtual mock-up case study on the Mission Hospital, the exterior framing and glazing case study for the Westminster project, the interior framing case study, plus a new MPS LOD Playbook featuring Primitives. We’ll share more prefab solutions from the Trimble Buildings family leading up to the Denver BIMForum. We hope you’ll be inspired to learn more about our construction solutions and then have the chance to follow-up face-to-face in Denver.
Trimble Buildings is hosting the Welcome Reception at the Denver BIMForum
on Monday evening, October 7. We look forward to meeting you and your team and hearing about your own success stories. We’ll have local craft brews to welcome you to our backyard, plus many of our product experts from Tekla, Trimble Field Solutions, SketchUp, Vico, Prolog, and WinEst. So please plan on joining us.
If you’d like to schedule a private demonstration, please use this form to suggest a time and we will work out the details. And if you can’t make the conference, use the form to schedule a private web demonstration any time this week or next.