Technical Insights by Kevin Ruston and Eric Westergren

McMillen Jacobs Associates has adopted the term “Design Technology” to describe the full range of applications we use during the design and construction process. It comprises more than just 2D CAD, 3D modeling, and Building Information Modeling (BIM) . It represents an umbrella that covers a broad range of software applications and workflows required to achieve the complex solutions unique to underground projects.

Taken as a whole, Design Technology represents more of a project delivery method than a computer-aided design process. The method reduces the boundaries between designer and drafter as both engage the tools in cloud-based collaborative environments. Design Technology adds tremendous value by increasing visibility into future realities throughout the design and construction process. Its ability, along with a proven track record, is driving demand up across the entire AEC Industry.
However, a major hurdle to Design Technology’s adaptation is that existing applications are not created with tunneling in mind. While certain components can be implemented successfully, there is no single BIM authoring tool that can define the full range of complex geometry common in our industry. This confronts our Design Technology team with a unique and rewarding challenge.

Currently, major BIM authoring tools are focused on the vertical market. This means there is not a complete set of tools available to define all geometry found on underground projects. To overcome this, we’ve learned which software applications possess the best solutions for given parts of the design. We’ve also learned to what degree we need to employ these solutions and how to blend them. The result becomes its own proprietary workflow that merges 3D elements from disparate sources into a project’s single, federated model.

To better understand our Design Technology approach, consider the holistic process. First, we review the specifics of a new project focusing on its characteristics. Then we identify where and when change is likely to occur during the design process. Next, we determine the best software solutions while identifying the limits of their implementation. For example, a typical water conveyance tunnel will have a bored tunnel (AutoCAD Civil 3D alignments, profiles, corridor modeling), with two shafts and valve chambers (Revit), mechanical piping (Revit), flared tunnel transitions and other morphological geometry (SolidWorks and or Rhinoceros 3D), a point cloud survey (Recap), clash detection and model reviews (Navisworks and or Revizto). And the list goes on.

Civil 3D corridor customized for underground tunnel model

Another challenge we face is how to customize “out-of-the-box” software features intended to solve problems in other markets. For example, AutoCAD Civil 3D’s corridors feature is a parametric 3D model element used to define surface features common to road, highway, and railway projects. However, with some customization and modification to the workflows, we can apply this feature to underground design models. The result is a fully parametric tunnel plan and profile drawing set that is nimble enough to keep up with alignment changes at any stage of a tunnel project (see image).

In summary, “Design Technology” is more than just computer-aided design. It represents a full suite of 2D and 3D solutions and workflows. For underground projects, it requires a blended approach that combines the best features of a wide range of software. But knowing how to use the software is only part of the equation. Knowing which solution to employ and to what degree becomes a vital part of its success. By doing so, Design Technology becomes more than the next generation CAD, it becomes a project delivery method that is technology based but relies heavily on implementation.

*For more information on BIM and Design Technology, see Segments articles in Volume 4 and Volume 13.