Although building information modeling (BIM) is a powerful tool on any project, contractors particularly like the ability to include nonstructural elements and further expand what the model can facilitate.
"We put our cranes and concrete pumps right into the model", says Dan Russell, simulated construction manager for general contractor Sundt Construction in Phoenix.
Incorporating major equipment enables the company to schedule equipment and crews as an integrated part of the model. As dimensions, materials, or other parameters change, the effects of these changes are automatically reflected in the schedule. Similarly, schedule changes in one area of construction - for example, a delay in completing the plumbing rough-in - are reflected throughout the entire model.
Sundt began using BIM about three years ago to better coordinate the mechanical, electrical, and plumbing portion of its projects. Once the company had the software, it made sense to use it in other aspects of work.
Today, the company uses BIM to generate a lift drawing, including embedded plate and rebar information, for every concrete pour. A 3D picture of each wall is also generated from the model, and such things as the square footage of forms and other quantity information are easily extracted.
Because all of the information is integrated, the entire model automatically shows the effects if one part of the model changes. For instance, if someone changes a concrete wall thickness from 6 inches to 8 inches, all the affected lift drawings are automatically updated.
Current Builders in Pompano Beach, Fla., builds parking garages as a design-build general contractor. David Thirlwell, BIM and virtual design and construction manager, started using BIM in 2007 to prevent coordination problems and produce better field drawings and now uses it for every new project. Developing each model initially may take two to three weeks, but after that he can quickly and easily create a drawing based on any task.
One example is a recent project in which a new, monolithic beam forming system was being used. BIM allowed Thirlwell to generate 2D section drawings of the garage that provided precise elevation data for placement of each form, saving hundreds of manual calculations and ensuring accuracy. It also revealed conflicting post-tensioning draw points at the ramp-to-column junctions and a surrounding apartment building.These were modified and adjustments were made in the production schedule that allowed better constructability. Because the potential conflicts were caught so early in the process, the changes were made without causing any delay in the field.
These were modified and adjustments were made in the production schedule that allowed better constructability. Because the potential conflicts were caught so early in the process, the changes were made without causing any delay in the field.
Although the company uses BIM in the framework of traditional design-bid-build projects, Thirlwell says its benefits are even greater in a design-build environment, especially when coupled with integrated project delivery. Such an environment, where all parties benefit from increased efficiency, encourages sharing as much information as practically possible. And incorporating BIM on a project dramatically expands the practicality of sharing data.