Transitioning to 3-D Design

April 2006 » Feature Articles
Like the 3-D world in which it operates, civil engineering is much better suited to tools that work in all three dimensions. Those tools are becoming more popular with firms every day.
Terry Bennett, P.L.S.-L.P.F.

Model-based design helps bridge the gap between engineering and construction work for efficient and profitable collaboration

Like the 3-D world in which it operates, civil engineering is much better suited to tools that work in all three dimensions. Those tools are becoming more popular with firms every day for a few simple, yet compelling reasons—clarity of information; streamlined collaboration; and improvement in that all-important 2-D notation, the bottom line.

As civil engineering firms are seeing the tangible business benefits associated with 3-D design, it also is important to remember that, like any advance in the profession, 3-D needs to be adopted deliberately and with the right training. Just as 3-D technology finds one of its most important uses in improving collaboration among various disciplines and stakeholders in a project, the same collaboration is vital to a successful 3-D implementation.

In any collaborative effort, clarity is key

Everyone needs to operate with a shared understanding of the task at hand. In 3-D modeling, clarity of information is a primary benefit. Holding a true 3-D model of the project to be built—or increasingly today, the one that is to be managed—provides the basis for that shared understanding.

It is a bit trite to say that a picture is worth a thousand words, but it’s a pretty accurate description of the clarity issue with 3-D. A flat, drawing-style representation of a project inevitably taps into people’s generic view of "projects like that." Using a 3-D design software program, such as Autodesk Civil 3D, provides all of the detailed information needed to interpret and understand the project. Instead of imagining what’s above or below, you can see it, and see the appropriate data that describe it.

Designers can extract the needed information from a model at whatever level is appropriate to the stakeholder—who, for security reasons, is viewing it in read-only mode to prevent editing—or to those working with the model directly. This is a vital aspect of bridging the gap that often exists between engineering and construction work. Everyone understands that designs and plans must be accurate. The question is how to ensure this happens through multiple handoffs and the overshadowing of liability.

Consider the traditional way of working, where a construction firm takes a 2-D engineering drawing set and then, often by hand, creates its own 3-D drawings for use in the field. What might be a 40- to 50-sheet plan set for engineering review and approval quickly becomes a 300- to 400-sheet set of shop drawings for construction. Any issue or misinterpretation on the engineering set has a massive ripple effect. What are the chances that these drawings will show the same project, but with different data, or are missing a key label or note? What happens when the project gets constructed according to this second set of drawings and turns out to be wrong? Now, you are looking at expenses you cannot afford and a potential liability nobody wants.

With the use of 3-D models, there is no need to go through the error-inducing step of recreating new drawings for each aspect of a project. The one model contains all the relevant information, and the technology used to create the model also can create a variety of views from the same data tailored to a particular project team member’s needs.

Therefore, construction documents are accurate representations of the project, minimizing errors and getting projects completed faster—a huge benefit in this age of early completion bonuses for many large projects.

Asset management The shift to 3-D is also a boon for an increasingly important aspect of civil engineering—the management of existing structures and projects. Using 3-D laser scanners, it is far easier and faster to create a detailed model of an existing project than by the tedious and often labor-intensive method of conducting a traditional survey, especially in hazardous areas such as highways or in areas with very dense data, such as bridges, tank farms, and underground utilities. Laser scanning can create a far more detailed and accurate model of a freeway overpass, a building site, or a bridge in much less time, and without missing information that later may be deemed necessary.

Laser scanning captures all of the data the first time

The same benefits apply in what is becoming a more common occurrence, when private enterprise is building and operating for a set period of time after completing what is essentially public infrastructure.

Known as build, operate, and transfer, this approach brings investment capital into cash-strapped jurisdictions and allows construction of more public infrastructure within existing budgets.

At the same time, however, these projects undergo the scrutiny of the public and oversight committees. In this process, a 3-D model has a tremendous advantage compared with traditional drawings in terms of obtaining faster approvals (because a project can be visualized easily in its surroundings) and making needed changes.

A change in the model database is reflected instantly and accurately on all views and plans.

Another advantage is obtaining realtime feedback by combining a 3-D model with geospatial information. For example, consider building a few miles of roadway using a model of the project combined with a highly accurate map of the location and construction equipment with built-in GPS. This can provide real-time feedback as to how the construction process is at variance with the model, and allow instant corrections. Using this approach to prevent spreading just an extra 6 inches of gravel on a couple miles of roadbed could save hundreds of thousands of dollars in otherwise wasted materials. In some cases, the simple elimination of the need for repeatedly staking each point means crews can operate with lights 24/7 in shifts, dramatically reducing construction time.

In addition, moving to 3-D can create completely new and more efficient ways of realizing large and costly projects. For example, constructing a large-scale housing development which has several planned phases is a long and expensive undertaking.

Traditionally, a developer might choose to make Phase I the area closest to the main traffic artery serving the development, building future homes farther inside the development. Using technology such as Autodesk Civil 3D, the developer instead can model the entire process before the first dirt is moved—lay out roads, mark out parcels, understand drainage, even match the right home style to the parcels. At the same time, this model can enable development of a more intelligent workflow to construct the project in the most efficient way. It may make the most sense to build Phase I homes well inside the development’s boundaries so excavated material can be moved more easily and reused in later phases.

The move to 3-D also can help firms play a larger role in the movement to sustainable design and "green" building. As architects, engineers, and developers look to satisfy client demand for green projects—those with the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) certification—they are considering more than simply using recycled building materials or ensuring efficient energy usage. Among other things that fall under the green umbrella include recovering a brownfield as part of the project. This is a case where a 3-D model is imperative because you need to know exactly what is buried where and how far down. Another help toward LEED certification is adding wetlands to a project or minimizing the length of road needed to service a development to leave more open space. Using models (including accurate GIS information embedded in them) can help a developer and designer identify the best way to add that wetland and most wisely use the land asset.

A 3-D transition Similar to anything else that offers these kinds of bottom-line benefits, adoption of 3-D modeling is not something that can be done overnight or without the investment of time and resources. This is not an upgrade.

To be successful in the move to 3-D, following are some practical tips for making the transition: Start small—This is not the time to throw new technology at a huge project that is behind schedule in the hope that there will be instant, project-saving efficiencies. There will not. You will simply wind up making things worse.

Instead, begin the transition with a pilot project, something familiar and, in general, easy for your firm to manage. From there you will gain enough experience, and key staff members will develop the expertise with the technology, to create a realistic rollout schedule for the firm overall.

Make it a team effort

Because this technology and the process changes required cross groups and disciplines within a firm, it needs to be implemented with input from everyone. People are naturally reluctant to change familiar work habits and procedures, but this is where many of 3-D modeling’s benefits lie. So, create a small working group within your organization to manage the change. It should, at a minimum, include participants from the IT department, the GIS department, and the engineering department.

Keep the team lean. The goal is to get the implementation done; too large of a group will get bogged down defending old procedures.

Instead, have three or four people who can answer the following important questions: How do we set up the company to best use these tools? How does each department leverage the process? Who needs to be trained first? The team needs to create new, standardized company practices and get past the "silos" that may exist between departments, which slow the adoption of any technology. When this is done, those team members become vital agents and evangelists for change.

Think beyond the model

There is more to 3-D modeling than the core technology.

Because of one of the technology’s inherent strengths, it is both possible and expected that you will share the model with all stakeholders in read/write form, or maybe just read only—including those who are not professional engineers or contractors.

Use technology such as DWF to share the appropriate views with people inside and outside the firm in a secure way. And because every view of a project uses the same database of information about a model, set up parameters for those views that strictly control who can change information.

Train, train, train

You are asking people to change habits, and in some cases, pretty old habits. Moving to a product such as Autodesk Civil 3D means thinking about parameter-based design, about styles rather than drawing layers. You will be moving away from using CAD, and will instead be installing an engineering desktop.

Engineers who are accustomed to working things out in a CAD program and then turning things over to a draftsman to pen a drawing will have to change their work habits. There is no alternative to an investment in training. This will take some time. The upside is that once you have completed the right training, your productivity will skyrocket.

Terry Bennett, P.L.S.-L.P.F., a senior manager of Industry Solutions for the Autodesk Infrastructure Solutions Division (www.autodesk.com/civil), manages its land development, civil engineering, construction, and transportation industry solutions. He can be contacted at terry.bennett@autodesk.com.


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