December 3 2020
Creating Transformational Bridges with Parametric Modelling: A Case Study
The Port Lands is a 400-hectare district currently undergoing massive development that will see it revitalized for Toronto’s growing population. The Port Lands Flood Protection and Enabling Infrastructure Project (PLFPEIP) has two primary goals: comprehensive flood protection for the Port Lands, as well as the creation of crucial infrastructure that will support creative and economic growth in the area.
Entuitive was retained by Waterfront Toronto as the Prime Consultant for the PLFPEIP Bridges and Engineering Contract. Managing eight subconsultants, Entuitive’s scope includes the design and construction administration of four new signature bridges (Cherry Street North Bridges, Cherry Street South Bridge, and Commissioners Street Bridge), the preliminary demolition design of the existing Cherry Street Bridge, and the design of a new Lakeshore Bridge over the Don River and the Harbour Lead Line Railway Bridge. The signature bridges will accommodate vehicular traffic, an interim BRT, future LRT, dedicated bike lane, and generous sidewalks that will double as leisure space.
The schedule was very fast paced and demanding, so our team didn’t have a lot of time to spend on modelling the complex geometry of the bridges in our structural analysis software.
In order to analyze the bridges in our software, the model needed to be divided into finite elements, also known as meshing. Meshing is the process of dividing the structure into discrete parts or elements in order to analyze the internal forces and overall behaviour of the structure. It allows us to ensure structural soundness.
3D Model of the Cherry Street North LRT Bridge.
The auto-meshing tools within Rhino and SAP2000 were not capable of modelling the complex geometry of the curved bridges with the required accuracy, and manual meshing would have taken too much time, especially with the tight schedule.
To solve this challenge, our team used computational design techniques to speed up the process of generating a structural computer model to perform our analysis. Using Grasshopper, we utilized a more advanced set of meshing tools that could more accurately represent the curved geometry of the bridges. This allowed our team to model the bridges within the tight project schedule.
Grasshopper model of Cherry Street North LRT Bridge before conversion to analytical model.
Analytical model of the Cherry Street North LRT Bridge in CSiBridge.
Parametric modelling tools provide value in terms of time savings and accuracy to any project with complex geometries. These tools, such as Rhino and Grasshopper, allow users to build generative algorithms that analyze structural designs more efficiently and effectively, running through thousands of design iterations to find the most optimized solution. A feat that would be very time-consuming by hand.
How Entuitive Is Investing in Advanced Technologies
Entuitive is active in the research, development, and industry education of these tools in order to continue providing uncompromising performance to our clients and remain at the forefront of engineering. Project such as the Port Lands Bridges make clear how valuable parametric modelling tools are for transformational projects that we take with us into the future.