Tipniques: Bridge Information Modeling (BrIM) Baby Steps

July 5th, 2012

Integrating basic BrIM into day-to-day bridge design isn’t difficult if you keep your objectives simple, focused, and organized.  At Autodesk University 2011, I enjoyed long discussions with several industry leaders and representatives for bridge engineering and construction firms regarding the implementation of Bridge Information Modeling.  The desires I heard from these professionals regarding BrIM as it applies to the bridge design industry vary from an eagerness to have a fully-modeled structure with integrated intelligent objects, to an inclination towards a stable and simplified 3D model depicting accurate internal reactions between key structural elements.

With the exception of some very large projects, BrIM in our day-to-day design and construction does not have the software flexibility-to-budget ratio to punch out our bread-and-butter Civil/Structural bridge projects.  However, it is very exciting to see the advancement Autodesk is making with tools such as Civil 3D, Revit, Navisworks, and Infrastructure Modeler.  In the near future, we will have new integrated software tools to aid us in developing fully-modeled and unique Civil/Structural sites. 

But what kind of Bridge Information Modeling can we deliver while we wait for more flexible tools?  What processes currently give the most return on investment for your standard bridge project?  And how do we ensure adequate collaboration between Engineering Consultant, Contractor, and Client?  Well, let’s discuss some nice day-to-day tips to aid you in building your BrIM processes and procedures while preparing for more integrated BrIM projects down the road.

Tip #1: Prepare Your Foundation

BrIM isn’t quite there for the bread-and-butter projects.  But we anticipate a steady and gradual transition to a fully-functional 3D modeling environment.  So let’s be prepared by keeping an updated library of standard Civil/Structural blocks, assemblies, and 3D components.  Depending on the number of clients and contractors you work with, managing this database can become extremely time-consuming.  Estimate what you need to keep current, and what you can let slide.   Don’t forget to keep an eye out for changing industry standards.  Building and organizing these basic elements will drastically reduce the setup time on future projects.

Developing and maintaining Civil 3D assemblies for roadway corridors and bridge sections is essential for moving towards your BrIM goals.  These assemblies can become extremely complicated depending on your roadway approach corridor and structure type.  But the benefits are well worth the time.  Even if you have an independent Revit or AutoCAD 3D model of your structure, a quick push of a current assembly can efficiently show conflicts within your design.

Figure 1: Assembly of Bridge Deck Utilizing Subassembly Composer 2012

 

Tip #2: Informally Train, Formally Train, and Train on the Job

Start your informal training by conducting basic research on BrIM tools and production methods.  When you identify the tools and methodology that provides the best results for your design style and client needs, begin gradual, independent training on your own.  Just prior to a project starting up, procure formal training on your software and the techniques.  Then immediately begin working on your BrIM project.  Two things will happen if you perform your formal training too soon.  First, you or your users will forget some of the processes and procedures.  As the old learning adage goes, “If you don’t use it, you lose it”.  Second, the software will change.  BrIM technology is advancing so fast that it is preferable to use the current version of Revit, Navisworks, or Civil 3D to take full advantage of the new or refined tools.

Tip #3: Coordinate With Design Engineers

Our design Engineers typically use highly specialized software such as CSiBridge, LARSA 4D, and ADINA.  Develop methods of importing or checking your 3D model against their design model.  At this stage of the game, you don’t need to have a full integration of their mathematical design information.  But a little collaboration between your Civil 3D or Revit model and their mathematical design model is an excellent way to promote quality assurance while training people to think in a more BrIM-orientated design environment.

Figure 2: Stress Analysis of Bridge Deck Using CSIBridge


Tip #4:  Identify Where You Need To Model

A bridge site is a very unique and dynamic design environment.  Although bridges can use the same general parts, or utilize common construction methods, the design of the structure and approach roadway can widely vary.  This uniqueness makes a full model of a common bridge design a little clunky and somewhat unnecessary for your average site.  Sure, if you are producing a signature bridge, you will strongly desire, and probably require, a functional intelligent 3D model.  But if your structure is a simple precast concrete girder system, you can probably find the best economy utilizing a basic 3D model for visualization purposes and BrIM level models for trouble spots.

Figure 3: Steel Collar Inside and Around a Column, Modeled for Seismic Analysis

We will typically develop cost-efficient models of trouble spots.  On our more simple bridges, this involves modeling the top of deck, the columns, or troublesome rebar locations.  We can create these 3D objects in Civil 3D, Revit, or vanilla AutoCAD, but identifying the conflicts between elements still requires the sharp eye of the CAD Designers and Engineers.

Figure 4: Rebar Conflict Analysis within a Concrete Arch

Tip #5: If You Create a Full Model, Don’t Model Too Early

Due to the dynamic nature of the Civil/Structural design process, we can end up tweaking everything from simple rebar layouts to the dreaded full re-alignment of the structure during the course of a project.  These changes can be catastrophic to your model and your budget should you develop an intricate model too early in the design process.

Figure 5: An Intelligent Design Model of a Signature Bridge

Tip #6: Don’t Promise More Than You Can Deliver

Public agency clients are forecasting reduced budgets, operating with reduced staff, and facing strong public scrutiny.  They are not in a risk-taking mood.  Therefore prior to agreeing to perform a BrIM-related deliverable, you must identify the type, accuracy, size, and delivery method of the model.  If you promise too much and are unable to deliver on time or within budget, you may sour your ability to perform future BrIM work with your client.

Bridge Information Modeling is the future of the Civil/Structural design industry.  As technology continues to allow integration and data linking of the mathematical, conceptual, and design models, these intelligent objects will become a standard addition to our deliverables.  By enhancing your work environment with a focused and gradual BrIM migration strategy, you will build a bridge to the future of Civil/Structural design development and delivery.

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Reuben Stone is a Senior Bridge Design Technician for David Evans and Associates, Inc. in Salem, Oregon.  He has over 10 years of experience working in Civil Structural Design, Light Rail, and CAD Project Management. http://www.linkedin.com/pub/reuben-stone/27/382/893

 

 

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