Introducing the one of the winners of The Steel Lion Award 2024. The article includes a detailed case study of Pangolin design for the creation and design of formwork structure.

THE CHALLENGES OF SPECIAL FORMWORK

Control throughout the design process is crucial, and even more so when it comes to structures whose loads change throughout the design process, as they are the result of a phased analysis that aims for an optimum.The field of special formwork is one of these areas.

Structures that: must support large loads (weight of fresh concrete) without showing large deformations to obtain the required concrete geometry, with the lowest possible weight so as not to stress the base structure, and which depend on environmental, production, technical conditions, etc.

The design of elements can become a constant back and forth of data between the calculation office and the design office, almost until the last day of the project.

STRUCTURAL CONCEPT

The structure under study is essentially simple (as the initial conception of any structure should be). It is a central structure supported on the central box girder of a bridge deck and can support the load transmitted by two 12 m long cantilever elements, which serve as formwork for the deck’s flanges and as a working platform for the installation of other structural elements.

This structure would be sliding on the central box girder. The formwork workflow would be as follows: 

Each of these described phases generates a set of loads that depends on the procedure with which it is carried out and that the different departments (mechanics, hydraulics, formwork, etc.) generate. These loads, coming from partial models, were introduced at previously agreed points and kept fixed by all departments throughout the project as far as possible. 

In a context of short deadlines, centralizing, coordinating and being able to maintain the rhythm of calculation and design of the elements that make up the structure is essential. A correct BIM flow, in which the Structural Designer is the BIM Manager, in this type of projects with very specific loads is a basic requirement that transfers trust and control to our partners and collaborators. 

The connection of Consteel through its Pangolin plugin to the Grasshopper graphical programming interface provides the necessary power to combine parametric elements that adapt to a geometry that, as in any project, is continually changing and data management through lists. 

GENERATION OF CLEAN AND COMMENTED ALGORITHMS 

As in any code, the comments and organization of the algorithm are an important part of the process and consume a large amount of time that at first seems useless but is very profitable when the project extends over time. 

For the case under study, the algorithm groups generated are the following: 

• Input parameters: control panel of all the external geometric variables of the algorithm. 

• Basic geometry: this group depends only on external geometric variables and should not be manipulated by any member of the team. In this section, the introduction points for other external variables such as loads are generated. 

• Data for Consteel: through Pangolin, they are entered as an external variable and through a list: 
  • The sections to implement in the different frames.
  • Releases at frames end.

• Geometry for Consteel: through Pangolin, taking advantage of the geometric entities generated in group 2: lines and points. A subgroup is generated for each type of element. 

• Loads for Consteel: through Pangolin they are generated and remain as the final external variable. The parameters to produce are: 
  • Loads: assigned to the defined points in group 2,
  • Load groups,
  • Load cases,
  • Combinations.

INFORMATION MANAGEMENT 

The shared information from the design departments is channeled, centralized and filtered to the model through the fields provided for the entry of external variables by the algorithm manager (structural engineer).  

It is important that there is a prior coordination phase with the design team in which the shared data and its format will be established. 

CONCLUSIONS 

• The use of algorithms that automate and simplify data entry into complex models is a way to reduce errors in the final design phases. 
• These algorithms allow sharing models in intermediate design phases that will serve the design department for a better understanding of the behavior of the system and therefore better load optimization. 
• The centralization of continuous changes in parametric algorithms allows obtaining structural models in constant evolution. 

If you want to get inspired by the work of other submitted Structural Engineers, take a look at all projects on the website of The Steel Lion Award.