Civil engineers have used 3D model-based design for over 2 decades, so the line between CADD and BIM is not clear. Using examples drawn from real bridge, tunnel, highway and transit projects, we discuss how to differentiate between CADD and BIM. We find a place for analytical models, introduce terminology, such as level of development (LOD), and identify how goals, processes, products, and applications differ through the project lifecycle. We also make sense of CADD Standards, construction plans, and 3D deliverables in the context of a BIM workflow that manages liability. We document our discussion in a Venn diagram that helps to communicate what BIM means for infrastructure.
- Set goals for BIM on infrastructure projects
- Develop 3D engineered models with appropriate LOD
- Describe how CADD fits into a BIM workflow
- Use BIM to develop standard deliverables alongside cool BIM deliverables
Kevin Gilson is the Manager of Design Visualization for Parsons Brinckerhoff, an international transportation planning, design and construction management firm. He manages 3D modeling and visualization programs for large infrastructure projects worldwide. For the last several years, Kevin has helped promote and implement new technologies such as Building Information Modeling (BIM), Virtual Design and Construction (VDC), and 3D model-based design solutions on several large infrastructure projects. Kevin has presented often on 3D modeling, visualization, and BIM/VDC processes, and has presented several courses previously at Autodesk University. Kevin spent several years as an Autodesk/Discreet Training Specialist.
Francesca is a member of PB's Special Services Group, a group focused on applying emerging technology and innovative concepts to complex projects. The Virtual Design & Construction group provides guidance and leadership on the application of BIM for infrastructure projects at the proposal, design and construction phase. The project portfolio includes signature bridge replacements and complex tunneling projects. Recognizing the strong industry penetration of model-based design for transportation projects, the VDC group specializes in integrating 3D design models to inform project management decision-making. The group uses BIM Implementation Plans to execute tasks, slicing and supplementing 3D design models to form a consolidated 3D model at the LOD and disaggregation required to deliver the BIM goals. These goals frequently include constructability assessments, high-level 4D schedule visualization, LOD 400 virtual mock-ups and LOD 400 clash detection of precast concrete elements.