Trimble Westminster Concrete 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 who produced the rebar shop drawings for fabrication, Harris Rebar did the fabrication, JD Steel performed the rebar installation, and JE Dunn’s own self-perform concrete team. 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.
Caption: Trimble’s new four-story, 125,000 sf office building in Westminster, Colorado
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.
SCI used Tekla to design, engineer, and check design requirements for the concrete,
reinforcing bar, steel embeds, structural support steel, steel stairs, steel decking, structural concrete slabs, and exterior structural metal framing. As stated earlier, they also produced the rebar shop drawings. The team then determined the detailing requirements according to the actual concrete schedule. The in-model analysis of the rebar shop drawings allowed for review, approval and return of the submittals within one day and fabrication and delivery of the rebar loads within 5 days of approval just in time to meet the fast-tracked construction schedule.
Caption: Tekla xray view of structural steel, concrete, rebar, anchor bolts, layout points, and utility piping
JE Dunn Construction also utilized Tekla Structures for constructability review, pre-planning concrete pours, production of concrete lift drawings, clash detection, and production of layout points for direct export to their Trimble Robotic Total Station (RTS633) utilizing the Trimble Field Link Tablet for 3D model viewing during layout. The concrete elevator and two stair cores models included accurate embed information from Zimmerman Metals, the structural steel supplier on the project, who utilized Dowco Consultants Ltd for their steel detailing. The 3D Tekla steel models were referenced against the 3D Tekla rebar drawings and 2D formwork supplier drawings to ensure constructability of the cores allowing embeds to be moved during the submittal process to avoid other embeds, rebar, or formwork ties/flip pocket in lieu of in the field during concrete form erection. The coordination of these items during the submittal phase combined with the use of the RTS for layout of all concrete on the project allowed for a 4 week, 33% time savings, over the initial project schedule and 35% reduction in the formwork labor budget.
The Trimble Robotic Total Station was used extensively during the concrete phase of the project for almost every aspect of installation. The concrete pier center points and 4 offsets for each pier were set for each of the 82 pier locations. Excavations were verified before any formwork was placed into the holes where each concrete corner,
pilaster and door block out locations were laid out with the RTS. All anchor bolt locations were laid out to within 1/16” accuracy during formwork, again during concrete installation allowing adjustment of the forms, and again after backfill to ensure the large earth moving equipment did not alter the installations.
Caption: Westminster West Stair Core (feft) and Pier Cap with Anchor Bolts Checked Just After Concrete Pour (right) with JE Dunn Layout Foreman utilizing the Trimble RTS 633, Trimble Field Link Tablet, and Trimble MT1000 (Active 360* Prism)
The concrete structural elevator and two stair cores were all laid out utilizing the RTS 633 with each corner and door opening marked on the previously poured piers or foundations to ensure proper rebar clearances inside the formwork. The MevaLite
formwork system was checked with the RTS prior, during and after the concrete pours to ensure the enormous pressure exuded by the liquid concrete and concrete pump system did not move the formwork from the designed location.
The RTS was also used along with Spectra Laser Levels later to provide grid lines and
benchmarks at each floor allowing for the installation of the steel stairs prior to steel erection. The elimination of temporary stairways or ladders during the construction provided for a safer and more proficient work environment and helped reduce the overall schedule.
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 anchor bolts, embeds and block outs required for the structural steel and stair erection and set the stage for a more efficient structural steel and concrete deck installation.
Caption: Here’s the stair and elevator shafts in use today!
We’ll share more prefab solutions from the Trimble Buildings family leading up to the Denver BIMForum. For example, check out a Steel Case Study, an Exterior Framing and Glazing Case Study, an Interior Framing Case Study, a Virtual Mock-Up Case Study, and a new MPS LOD Playbook featuring Primitives. 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.