ACHE, the Spanish Technical Association for Structural Concrete, has awarded its Second Prize, Innovation Category, to the Roof Replacement of the Cathedral in La Laguna, Tenerife, a restoration project we worked on between 2011 and 2014 as consultants to the Structural Engineers, CESMA Ingenieros.
This prize is part of the third edition of ACHE’s Structural Engineering Awards and we are extremely happy about the news for many reasons. ACHE is, probably, the most prestigious institution of its kind in Spain but also because the prize recognises the value of the work completed by CESMA, by the Architect José Miguel Márquez and by the Contractor in a project where science and technology helped overcoming economical constraints.
The Cathedral was completely rebuilt between 1905 and 1913 using a rather new material for that time: the reinforced concrete. The advantages in execution speed and reduced cost it brought were at the expense of an unknown technology which eventually resulted in the complete damage of the roof that forced to keep the building closed for 12 years. A new rebuild was necessary and this time it was decided to completely replace the roof and to employ special materials like concrete with fiber or plastic rebar reinforcement in order to ensure a lasting structure.
Within this framework CESMA Ingenieros, with the leadership of Engineers Peter Tanner and Juan Luis Bellod, brought us into the project to help with 3D information management and to ensure correct geometrical and constructive compatibility. Once we had understood the scope, Modelical developed the following tasks:
- A Preliminary design model were performed from the existing CAD survey. This model should help CESMA work with their Finite Element Analysis tools in a consistent way, ensuring correct mesh properties and according the input from the design engineer.
- Global parametric model that helped validating a prefabricated approach. As the columns, once the roof had been removed, would arrange along an irregular grid, we proposed a study to evaluate the expected distortions if a regular, prefabricated scheme of vaults was applied. The goal was to validate if the replacement of the roof could be done using repetitive items, in spite of the considerable distortions resulting from a 100 years old building. The results of this assessment recommended an in-place approach.
- Detailed parametric model that could help limiting the number of different arc formwork typologies by applying small adjustments in the keystone. As an in-place approach throughout the works had beed agreed, we focused then on reducing the complexity or construction methods by limiting the number of unique formworks the contractor should build and use.
- Detailed model for vault formwork layout. We used Rhinoceros and Grasshopper to supply the contractor with enough and precise data for correctly placing each vault’s formwork in a fast and easy way.
In summary, the Replacement of La Laguna Cathedral Roof is a clear example of the power of parametric modelling at the service of responsible design and modest execution resources, with a strong BIM vision that turned our models into a common discussion platform for project and construction decisions.
If you would like to know more about this work or about the ways we can help reducing complexity in structure and restoration projects, please get in touch or just leave your comments below.