English |Dutch en | nl
How safe are the road bridges in Amsterdam? Iv-Infra Conservation Innovation Unique projects

Project assignment

Amsterdam has around 1,600 bridges. Many of these bridges were designed and built decades ago, and for considerably less heavy (freight) traffic than of today. The municipality manages and maintains the bridges in a risk-based manner, which involves having to continuously identify which risks threaten the functioning of the bridges and/or the safety and establishing how these risks can be managed. The ‘Constructive Safety of Bridges Programme’ assesses the bridges for safety within a multi-year programme whereby an assessment framework, with which the bridges in Amsterdam can be assessed, is being developed. There are approximately 850 road bridges to be tested under the programme as the volume of traffic has changed considerably for these bridges.

Establishing a well-founded prioritisation

What is the current structural condition and structural safety of these bridges? Do they still meet the latest load-bearing capacity requirements? And which maintenance measures are required? Iv-Infra and Movares are mapping this together for roughly 300 road bridges. By doing this, it is possible to establish a well-founded prioritisation for the required approach of maintaining the bridges in the coming years.

Objective representation of the constructive state

Insight into the area surrounding bridges is obtained by drawing up maintenance analyses and, where necessary, performing recalculations of the civil engineering works. The assessment process consists of three steps

1. Establishing an initial risk profile and priorities, based on archived data.
2. Further investigation (on-site constructive inspections, possible material investigations, possible recalculations).
3. Establishing a definitive risk profile for the purpose of determining the safety level and the control measures to be taken.  

The maintenance analyses are carried out based on available information and documentation, previous maintenance and other relevant management and maintenance data. With this information and the specialist expertise of constructors and inspectors, an Object Risk Analysis (ORA) is drawn up, which is used for further in-depth inspection and verification of the information. The findings are analysed and processed in the municipality's database. The result is an objective representation of the structural state of the bridges which also provides insight into the control measures to be taken.

Utilising the budget efficiently

Should there be any uncertainties or doubts regarding the scope or cause of damage, further investigation will be carried out. In consultation with the municipality, the civil engineering works, of which the constructive safety is unknown or in dispute, will be recalculated. Should it be the case that certain material properties (required for the recalculations) are unknown, these will also be identified.

The recalculations are carried out in accordance with the prevailing standards and guidelines and are tackled step by step in order to utilise the clients’ budget as efficiently as possible. This method has already been tested with the Directorate-General for Public Works and Water Management (Rijkswaterstaat) and is also being used by other municipalities that have a similar task for their civil engineering works. This phased approach ensures that the focus is tailor-made for each civil engineering structure and that any unnecessary inspections (which may cause hindrance) or in-depth calculations are avoided.

Not everything is possible all at once

As more insight is gained into the structural condition and safety of the road bridges, Iv-Infra and Movares advise the municipality on improvements in the assessment framework, the approach and the prioritisation of the bridges. Since not everything can be tackled all at once, we also advise the municipality on any temporary measures required (auxiliary structures or monitoring) or the deployment of innovative means.
Would you like to know more about the possibilities for your project? Wouter will be pleased to share ideas about your engineering issues. Contact him by email or call​ 088 943 3200.
We are always on the lookout for new talent. How can you strengthen our team? Working at Iv means working on challenging and varied projects every day. At the office or on location. Check now to see if you can find an exciting challenge within your specialism!