Design of an aluminium deck on a steel girders bridge with Advance Design America – Bridge

In 2020-2021, WSP was chosen to prepare the detailed plans and specifications for the construction of a full-scale prototype bridge in Université Laval’s Montmorency Forest.

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Design of an aluminium deck on a steel girders bridge with Advance Design America – Bridge

Company: WSP

Project submitted by Benoit Cusson, WSP, Canada

Context

In 2020-2021, WSP was chosen to prepare the detailed plans and specifications for the construction of a full-scale prototype bridge in Université Laval’s Montmorency Forest.

This 15 m long by 8 m wide bridge is intended for highway traffic load and forest truck loading. It is also designed to be pre-assembled in the factory and installed on site in a matter of days. More specifically, the aluminum extrusions are welded longitudinally to form four panels which will be assembled using blind bolts. The deck is supported by three steel girders. Special flanges partially connect the deck to the girders and allow free expansion in both horizontal directions as well as non-composite action.

 

Customer Challenge

Qualifying this structure as non-conventional, Benoit Cusson, designer on this project needed software that would allow freedom in design. For example: the flexibility to place nodes, members, and plate elements where he wanted them to be.

Solution

Given that Graitec’s design and analysis solution allows this in a very transparent way, Mr. Cusson chose to work with Advance Design America Bridge (ADA).

Mr. Cusson, who was already an active user of Graitec’s ADA Bridge software expressed his appreciation, “I enjoy working with ADA Bridge because it leaves me the perfect degree of control over what I do. This is still what I like the most about the software. For example, I use the shape calculator to import my aluminum extruded shape. Then, I let ADA calculate section properties for me.”

Among other software capabilities, Mr. Cusson mentioned:

  • The very good 3D visual of the structure which was very helpful when presenting to the customer.
  • He was also able to change the geometry of the structure easily, and test different patterns and different geometries. This helped confirm which scenario was the best. One good example lies in the fatigue loading. Code says we must run moving loads as trucks in a design lane. But what is a design lane? The engineer or designer can decide that. In this project, Mr. Cusson was able to decide where the design lane and reference line should be, by performing a sensitivity analysis, moving that lane transversely. This is how he managed to find all the critical locations that would make his bridge successful for SLS, fatigue checks and more.
  • He also enjoyed the ability to input all the load combinations themselves. To keep control over that, he worked in Excel file separately. When it was time, he simply had to import this file using the very efficient copy paste tool in ADA. To this, Benoit Cusson mentions: “I like that level of control. I like that it can be transparent like that”.

When working on this project, Mr. Cusson separated his model into upper, middle, and lower parts of the model. This meant 3 different structural model files.

The first, the aluminium deck, was modeled separately, with virtual supports to help figure out how it was behaving.

Separately, he did steel girders. Although quite classic, he still needed to make sure that design was fine as well.

Lastly was the foundation level. When the time came, he simply had to move some nodes around and connection automatically lined all these layers together, providing the full 3D complex behaviour of that innovative structure.

Mr. Cusson commented on the software’s ease of use: “When I wanted to separate the model again, to change the design, it was just as easy to do. ADA is open. You can do whatever you want with the nodes and the members. It’s not parametric. You have control over what you do and you see everything you need to see.”

During that complex project, Mr. Cusson had to contact technical support on multiple occasion, and he is very happy with the customer care received. Good technical support in a timely manner is critical for him.

Bio notes

 

Benoit Cusson holds a bachelor’s degree in civil engineering from the École Polytechnique de Montréal and a master’s degree in structures from Laval University. He has ten years of experience with WSP and has a particular interest in complex structures and those using aluminum. He is a member of CSA S6 TSCs 13 on movable bridges and 17 on Aluminum Structure as well as the upcoming CSA S7 Guideline on the design of pedestrian bridges.

 

Picture: Farshad Pourshargh, GRAITEC and Benoit Cusson, WSP

Design of an aluminium deck on a steel girders bridge with Advance Design America – Bridge | GRAITEC CANADA
Design of an aluminium deck on a steel girders bridge with Advance Design America – Bridge | GRAITEC CANADA

“In our reality, our day-to-day, we don’t have enough time to troubleshoot and resolve technical problem ourselves. So, we turn to Graitec for quick answers and support team is always there to help resolve issues. Throughout the years and projects, I have always been able to count on Graitec’s software and their team and it’s truly appreciated. “

 

Benoit Cusson, WSP

 

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