Groningen in the Netherlands is the site of one of the largest natural gas fields in the world. Extraction started in the late 1950s but, within 30 years, it became clear it was causing seismic activity. At first this was on a fairly small scale but in 2012 a stronger earthquake raised the question of whether more severe life-threatening earthquakes were also possible.In response, a project was set up to assess buildings in the area for seismic resistance and implement any necessary reinforcement measures. Royal HaskoningDHV has been working on the project with contractor Visser & Smit Bouw in a joint venture known as VIIA.
Time constraints and detailed analysis combine to create challenge
The task is immense. It involves around 100,000 buildings, none of which were constructed with earthquake resilience in mind. Most are built from masonry which exhibits complex behaviour during earthquakes. This complicates the challenge because advanced analysis is needed to accurately identify if a building is safe - and this takes time. If a quicker, less detailed analysis is used, the results are more conservative so more interventions would be required.
The project started with an assessment of 120 schools within a 9-month period. The challenge facing Royal HaskoningDHV was how to declare buildings safe and only strengthen when necessary while working at sufficient speed to cover multiple properties.
Unique methodology enables the project to grow quickly
Our structural design team used an unusual approach to the challenge. Instead of treating each school as an individual project, we developed a methodology based on similarities across buildings, analysis methods and steps in the process of analysis.
We created a uniform approach using very elaborate pre-filled templates. Protocols described the precise procedure for the engineer so the project could grow quickly.
Structural Engineer, Royal HaskoningDHV
Maurice Hermens continues: “At that time there was limited earthquake expertise in the Netherlands so we needed to educate people quickly and standardise procedures.”
The retrofitting of strengthening measures was approached in a similar way. The team created an online catalogue which identifies measures, when they are applicable, and which is best in particular situations. It automatically presents costs and visualisations. The Measures Catalogue has proved so successful that all the companies working on the project have been directed to use it. It has also won awards, including a Dutch Design Award in 2018.
Automation removes repetitive work from engineers
The standardised approach and protocols of the building assessment method enabled repetitive parts of the process to be automated using parametric techniques and scripts. Engineers make complex choices using the software which provides an optimal combination of speed and flexibility.
- ClientThe municipality of Groningen
- ScopeAssess and retrofit thousands of buildings to protect against earthquake.
- SolutionA project was set up to assess buildings in the area for seismic resistance and implement any necessary reinforcement measures. By adopting a different way of working and developing automated tools, Royal HaskoningDHV has created a methodology that is efficient, effective and scalable.