Time, Cost Benefits Realized with Advanced Modeling

In Quebec, Canada, Route 73/175 is a major north/south highway on both sides of the St. Lawrence River.

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By Casey Hibbard

In Quebec, Canada, Route 73/175 is a major north/south highway on both sides of the St. Lawrence River. The two-lane highway links the province with the picturesque, mountainous Saguenay-Lac-Saint-Jean region.

In a $5.8 million project, the Transportation Ministry of Quebec is currently widening the highway to improve safety for travelers and enhance the flow of traffic and goods between Quebec City and Saguenay-Lac-Saint-Jean.

Quebec-based Roche Ltd. Consulting Group, an engineering and construction company that designs and manages projects worldwide, is one of the engineering firms working on plans for the widening, which is expected to be completed in the summer of 2009. Engineering work on the highway project focuses on a three-kilometer section, which requires a 700-meter diversion of the Taché River near the Jacques-Cartier Provincial Park. Roche was challenged with designing the diversion in such a way as to protect the area’s wildlife habitat – beavers, fish, frogs, moose and birds. Then the company was required to present the plans to environmental organizations representing each of those species, and to the Quebec Ministry of Transportation, for approval.

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Figure 1: Route 73/175 is a major north/south highway on both sides of the St. Lawrence River.
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When the project began, Roche used the US Army Corps of Engineers Hydrologic Engineering Centers River Analysis System (HEC- RAS) modeling software. Roche’s engineers manually entered data into HEC-RAS from AutoCAD drawings and then drew computed HEC-RAS results back on the AutoCAD drawings. With 150 HEC-RAS cross-sections, complex bends, a bridge, and floodplain mapping, the work had already taken about a month and a half.

“The geometry of this project was too complex to easily model with HEC-RAS,” said Marc Labelle, Specialist Engineer for Roche.

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Figure 2: Engineering work on the highway project focuses on a three-kilometer section, which requires a 700-meter diversion of the Taché River.
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The firm decided to try RiverCAD from BOSS International. RiverCAD automates HEC-RAS and HEC-2 within AutoCAD and dynamically updates changes made to the model. This was especially convenient for Roche when they had to integrate feedback from the various environmental groups in charge of each of the protected species.

To properly protect the wildlife, Roche had to incorporate some innovative solutions, such as creating a place where moose could pass under the bridge and where beavers could make dams in the floodplain. As Labelle presented the plans to each environmental organization, he incorporated the feedback into the HEC-RAS model, resulting in repeated revisions. With the software, the changes were quickly integrated into the AutoCAD drawings and corresponding HEC-RAS model.

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Figure 3: With RiverCAD engineers were able to instantly re-cut HEC-RAS cross-sections.
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“We changed and revised the HEC-RAS model about 10 times until everyone was happy with it,” Labelle said. “With RiverCAD we were able to instantly re-cut HEC-RAS cross-sections, quickly change the diversion realignment and still incorporate the bridge structure and floodplain mapping.”

As an added benefit, the more advanced modeling was also easier to present to an audience. This hidden benefit turned out to be crucial when Labelle had to customize the output for presentations to each of the interested parties according to their level of expertise.

“Client satisfaction was much higher because they were able to see model complexities more easily and quickly,” said Labelle.

Roche Consulting recognized very quickly the added benefits of more advanced modeling software. The U.S. Army Corps of Engineers HEC-RAS model has its advantages: it’s free and is capable of getting the job done, especially on smaller projects. However, when a 45-day project can be reduced to 3 days, as it was in Roche’s case, the time saved with more advanced software can make a significant difference.

About the Author:

Casey Hibbard of Compelling Cases Inc. can be reached at 303-494-5785 or via e-mail at casey@compelling-cases.com. For more information on RiverCAD, please visit www.bossintl.com/rivercad-overview.html.

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