Can CIM Be Done in Civil 3D?
We’ve all heard the term Building Information Modeling (BIM) being thrown around for quite some time now. In general, BIM is the process typically applied to and associated with intelligently and dynamically designing an actual building or structure, where architects/engineers and designers can visualize and anticipate the true constructability of a project.
On the civil engineering side, we’ve been designing and modeling everything outside buildings/structures in a 3D environment for just as long, if not longer, than the term BIM has been around. However, for one reason or another, these designs have not typically been viewed as BIM by the vast majority. During this time, we’ve been able to generate and link surfaces, create corridor models and pipe networks. We’ve been able to produce dynamic profiles and cross sections, perform clash detections and earthwork quantities, and even generate reports and cost estimates. Although civil engineers and designers have been producing some form of a 3D model within their design over the years, the final product has almost always been a hybrid of 2D and 3D design components.
As we ride a new wave of AEC design and collaboration concepts, the industry as a whole is shifting its focus to a fully integrated ‘Design to Construction’ workflow, introducing the ability to streamline designs, reviews, cost estimates, constructions, and as-builts. To get us there, we are required to throw the 2D mentality out and fully embrace the concept of 3D.
By incorporating similar processes used for BIM, we understand that the full Civil Information Modeling (CIM) process doesn’t end with generating a 3D model. Once a true 3D model, or site representation, has been developed, we can move into additional dimensions that will allow us to extract and analyze the intelligent components put into our design.
As clients and owners discover the value and adapt to this new technology wave, it's becoming more common for them to make it a requirement for AEC firms to include their 3D models along with hard copy plan sets at each design deliverable. Contractors are also getting involved and collaborating at much earlier phases of the project design.
Since the introduction of BIM, contractors have been shifting toward this environment where they can update design models with additional construction intelligence while making in-field modifications/adjustments to the model during construction phases. This process, currently known as Virtual Design & Construction (VDC), allows for a more seamless collaboration, resulting in a much improved as-built final product.
CIM Procedures
With a growing demand for expanding our design capabilities to incorporate the ever-evolving enhancements and improved functionality with the various design programs, we are expected to continuously improve our skill sets and help guide each other during the transition from 2D to 3D CIM principles and concepts.
Implementing a true CIM design, especially the first one, isn’t accomplished easily. There will most definitely be some hiccups and growing pains along the way. You may even find yourself reaching the breaking point of frustration where you think that the only viable option is to go into survival mode and let old habits kick in. Rest assured, we’ve all been there and it has only made us better for it. As dim as it may seem at the time, there is a light at the end of the tunnel.
Traditionally, design costs and efforts typically take the biggest hits during the intermediate and final design phases of a project, whereas a CIM design will be front-loaded and taper off as the project design development progresses. Additionally, working in a 3D model-based environment drives individuals to really think about what they’re designing and how it impacts the rest of the project. More time is spent up front detailing a 3D model dynamically and intelligently in preparation of drawing generation and detailed analysis. As a result, any changes/revisions you encounter during the latter phases of a project will take significantly less time to update and adjust. It’s at this point that you will begin to see the major benefits behind generating a CIM design.
During project initiation/startup, project managers and engineers now need to look at the overall picture of the project and document what they want the final product to represent, and then determine how best to get there. BIM/CIM execution plans are becoming more commonplace, where design teams collaborate early on to put together a document outlining all of the BIM/CIM Workflows and Uses to be applied throughout the project life-cycle that will be most beneficial to reach that final product. Here are some example CIM Workflows and Uses:
Sample CIM Workflow
Logistics
Network Resources
- Setup
- Verification
- License & Privileges
Hardware Resources
- Acquisition
- Setup
- Verification
Software Resources
- Acquisition
- Deployment
- Licensing
Personnel Resources
- Staffing
- Training
Initialization
Project Planning
- CIM Team
- BIM Team
- Mobilization
- Modeling Strategy
- Integration Strategy
- New Project Setup
- Scheduling
Data Management
- File Transfer Protocols
- Dataset/Worksets
- Data Shortcuts
Model Management
Network Resources
- Linking Method
- Worksharing Method
- Holistic Approach
Designing/Modeling
- Design Phases
- Change Orders
- RFIs
- As-Builts
Quality Assurance and Controls
- Clash Detection
Deliverables
Soft Copies (Digital Files)
- Designs/Drawings
- Source
- Universal
- Reproducible
- Data/Dataset/Resource Files
Hard Copies (Printed)
Life Cycle
- Archiving Data (Digital Files)
- Enterprise Data
- Library/Catalog Updates
- Commissioning/Operations and Maintenance
- Lessons Learned
Sample CIM Uses
Planning
- 3D Modeling (Model Production)
- Bridge Modeling & Structural Analysis
- Cost Estimating (QTO)
- Design Options (Concept Study)
- Design Reviews
- Storm Drainage Design and Analysis
- Utility Design and Analysis
- Existing Conditions
- Geotechnical Analysis
- GIS Tools (Environmental Analysis)
- Phase Planning (4D)
- Roadway Design and Analysis
- Sustainability Analysis
- Traffic Analysis
- Visualization
Design
- 3D Coordination (Clash Detection)
- 3D Modeling (Model Production)
- Bridge Modeling & Structural Analysis
- Cost Estimating (QTO)
- Design Reviews
- Digital Fabrication
- Storm Drainage Design and Analysis
- Utility Design and Analysis
- Drawing Generation (Production)
- Existing Conditions
- Field Automation (Machine Guidance)
- Geotechnical Analysis
- GIS Tools (Environmental Analysis)
- Phase Planning (4D)
- Roadway Design and Analysis
- Sustainability Analysis
- Traffic Analysis
- Visualization
Construction
- 3D Coordination (Clash Detection)
- Bridge Modeling & Structural Analysis
- Cost Estimating (QTO)
- Digital Fabrication
- Storm Drainage Design and Analysis
- Utility Design and Analysis
- Existing Conditions
- Field Automation (Machine Guidance)
- Geotechnical Analysis
- Phase Planning (4D)
- Record Modeling (As-Built Modeling)
- Roadway Design and Analysis
- Site Utilization Planning
- Traffic Analysis
- Visualization
Operations
- Asset Management
- Cost Estimating (QTO)
- Existing Conditions
- Phase Planning (4D)
- Preventative Maintenance
- Record Modeling (As-Built Modeling)
- Visualization
It’s also necessary to investigate which design programs are available that will enable us to achieve full success on the CIM implementation. Both Autodesk and Bentley have an array of design programs and tools available that give us the ability to achieve full success on our CIM implementation.
On the Autodesk side, AutoCAD® Civil 3D was introduced more 10 years ago and has allowed us to dynamically design our models. This design process has become more seamless as Autodesk further developed the program through the years since. Civil 3D gives us the ability to produce 3D, 4D, 5D, and 6D models, but with limitations. Many will say there is still a need to revert to the 2D drafting mentality to lay out certain site features (i.e., fencing, erosion control BMPs, landscaping, etc.). Although somewhat time consuming and a little unorthodox, we can now generate a lot of these features dynamically with the use of feature lines, Subassembly Composer, Part and Content Builder, and various add-on design programs, tools and apps.
Furthermore, with the introduction of Infraworks a few years ago, we now have a program that will enable us to take our full Civil 3D CIM design and bring it into a real world setting where we can more accurately visualize how our design will be integrated with its surrounding site features/developments. We can further customize this visualization with graphics/textures, landscaping, animations, analysis, etc.—all while gaining an even better perspective of the true constructability of the design.
Incorporating Dynamic Blocks to Generate More Accurate Civil 3D Models
Figure 1: Exaggerated fence layout
In order for us to fully embrace the 3D environment, we need to completely change our way of thinking and designing. We continue to rely on custom linetypes to represent a lot of our site features being displaying on our plans.
By creating 3D elements in AutoCAD and converting to dynamic blocks, we can begin to remove at least some of the 2D linetype representations we so heavily relied on in the past to display various site components. The following example will go over the process of creating a dynamic block to replace a simple Civil Site 2D linetype.
Figure 2 is a picture of a typical chain-link fence in 2D view.
Figure 2: Typical 2D chain-link fence linetype
With the use of the 3D Solid Modeling built into AutoCAD (and available in C3D by switching your workspace to 3D Modeling), we can create an accurate 3D representation of what this fence should really look like. You would want to start off with a standard fence based on a detail from your local municipality. Keep in mind this block can be modified later on to accommodate any special requirements needed for different clients/owners or site constraints. Once completed, your new appearance will look like this in 2D and Isometric views:
Figure 3: New 3D chain-link fence linetype shows pole and foundation
Figure 4: Isometric view of new chain-link fence
Once you have your 3D representation set up the way you want it to look, we would then convert it to a block. In Block editor, we can add Parameters to define distances, points, visibility settings, etc. to better define how your block is, and should be, represented in 3D views. We can further manipulate it to apply Actions to each of the Parameters to define how you want the block to act as you lay out your site features in your Civil 3D models. In this instance, I have applied stretches to a few of my distances to give me the ability to extend poles and fencing along alignments as necessary. I have also added an array to my horizontal distance so that as I stretch my chain-link fence block, the poles will copy in an array along the alignment as well. In this situation, I have set my array to 10’ intervals/spacing.
Figure 5: Chain-link fence definition in block editor - 2D wireframe view style
Finally, if you switch your view display setting to realistic, you can apply the chain-link fence appearance to your block through the Rendering Materials Browser. You may also need to adjust the material mapping interval such that it looks like a true 3D chain-link fence with correct mesh spacing.
Figure 6: Chain-link fence definition in block editor - realistic view style
After you’ve set all your parameters and actions, save and close out of block editor. If you switch to your isometric view and select your new block, you will also see grips in places where you have defined your actions.
Figure 7: View of block as inserted into your working model
Figure 8: View after using one of the grips to stretch the chain-link fence block in your working model
Your block is now ready to be incorporated into your Civil 3D model.
Figure 9: Realistic view of chain-link fence
Figure 10: Realistic view of chain-link fence
Figure 11: Realistic view of chain-link fence
Conclusion
To learn more and post your thoughts about these topics, please visit (and join!) the Civil Information Modeling (CIM) LinkedIn group: https://www.linkedin.com/groups/8473326. Through this forum, members can share pertinent information with regard to CIM processes, provide updates on Industry leading design standards/practices/techniques, have open discussions, provide tips and tricks, and most importantly, to improve our overall quality, efficiency, and consistency across the board. Post away!
As always, feel free to contact me directly if there’s anything you would like to discuss.
Stephen Walz is a Senior Civil Designer and Civil BIM Liaison at HDR, a global leader in engineering, architecture, environmental, and construction services. Stephen has been in the AEC Industry for more than 14 years, 12 of which have been with HDR in its northeast and southeast regions. He has served as a member of HDR’s regional QA/QC Committees, and is currently a member of HDR’s BIM Steering Committee, Co-Chair of HDR’s Civil 3D Steering Committee, and Leader of HDR’s Civil 3D User’s Network. Stephen is also a steering committee member for Advanced Solutions’ Charlotte Civil User Group. Stephen can be reached for comments or questions at stephen.walz@hdrinc.com.
