BE Magazine - Volume 4, Issue 3 - (Page 33)

BUILDING opening, for example, a new wall panel would need to be formed and poured according to a newly produced set of drawings. Likewise, the site-cast wall panels must ﬁt precisely with the foundation and framing. Previously, LJB could coordinate the design of the framing and the foundation, but the panels had to be designed separately. With a 3D building model, LJB can create the building cross sections and elevations with the foundation and roof plans to ensure that everything ﬁts properly. Another advantage is the ability to extract data from the 3D model for use in calculations. For example, LJB designers developed a custom VBA application that uses panel and opening dimensions together with materials properties to calculate the center of gravity of a panel to guide placement of lifting inserts. A wall panel may require as many as eight inserts. The custom program automatically places all eight inserts, their dimensions, and a note showing the weight of the panel. Another custom program calculates how many cubic yards of concrete are needed for each panel as well as the panel’s weight—information valuable to the construction superintendent. LJB found that building information modeling (BIM) provided signiﬁcant advantages for tilt-up construction design. “BIM’s design automation capabilities prevent duplication of tasks,” said LJB designer Tim Coppess. “And it simpliﬁes design changes and reduces ﬁeld errors.” He estimated that over the life of a project, BIM technology cuts design time by 25 percent. “That brings two results: lower labor costs in design and higher drawing reliability.” v LJB used BIM for the tilt-up construction design of the Wells Fargo complex, which includes three interconnected buildings totaling 310,000 square feet (3D model above and photo to right) In 2000, LJB’s CON/STEEL division adopted Bentley Structural solutions and TriForma. LJB has customized Bentley Structural data sets to suit the specialized needs of tilt-up construction. The ﬁrm created a library of hundreds of structural shapes for placing all panels and foundations, and uses compound 3D cells for the connections between the concrete wall panels and the structural steel. The compound cells enable designers to take off quantity reports directly from the 3D model. Individual designers have also customized menus and tool palettes and written macros and VBA programs to speed up their work. “With Bentley Structural, the preconstruction drawings consistently reﬂect the as-built drawings almost exactly,” said Dan Steeley, LJB’s IT director. Improved accuracy Before BIM, any change to a design would require LJB designers to manually update every drawing affected by the change. With multiple sets of drawings required for many different purposes, it was easy to miss some. But by using a single 3D model, designers can easily ﬁnd and ﬁx problems such as a missing panel or an incorrectly placed panel opening. Mistakes that make it to the ﬁeld can be especially costly in tilt-up construction—sometimes increasing engineering costs just enough to turn a project from proﬁt to loss. To ﬁx an incorrectly placed panel Although it uses Bentley products, LJB is able to work with architects who use other design applications thanks to the interoperability of MicroStation. Moreover, Bentley Structural is capable of exporting data for steel fabricators who use Design Data’s SDS/2 steel detailing system. On the Wells Fargo project, more than 2,500 elements were exported to the SDS/2 steel detailing system, which in turn generated 600 sheets of structural steel fabrication drawings. The ability to exchange data electronically shortened the shop drawing schedule signiﬁcantly, said Steeley. LJB credits the efﬁciencies gained through BIM with helping it stay on track with the Wells Fargo project. Since multiple users can work on the same project simultaneously, two engineers shared the structural engineering work by splitting the project into ﬁve separate areas (three main buildings and two connecting Volume 4, Issue 3 | BE MAGAZINE 33

Table of Contents Feed for the Digital Edition of BE Magazine - Volume 4, Issue 3

Contents Rising to the Challenge News BE Newsletter Highlights More ITS Sightings Racing Concrete Canoes Lights, Camera, Action! Making the Cut People’s Choice Awards 2007 Executive Keynotes Building Clear Vision of a Dream Concrete Results Reaching New Heights Building News From Bentley Golden KIWI Awards 2007 Civil A Coordination of National Highway Proportions Training Troops Beautifying Highways, One Sign at a Time Civil News From Bentley Geospatial Facility Facelift Planning for Uncertainty Geospatial News From Bentley MicroStation at the Heart of LiDAR Surveying Solutions Plant Making the Grade Data Deja Vu Data Clouds Provide Clear Visual of Underground Saving Precious-Metal Mining Time Plant News From Bentley Advertisers Index Special/Academic The Art of Visualization Training Is Key To Delivering State-of-the-Art Solutions Bridging the Information/Infrastructure Gap

BE Magazine - Volume 4, Issue 3

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