The signing of the two-phase contract Renovation A12 IJssel bridges is almost 9 months ago. During this period, Savera IJssel bridges (a combination of Hollandia Services and Dura Vermeer) and Rijkswaterstaat have worked together as one team on phase 1. We would like to give an update on three crucial elements of this project phase.
Start of welding trials
In this first phase, we are carrying out inspections and studies to elaborate the existing final design into an execution design. We have jointly established that the steel quality of the now 60-year-old bridges is insufficiently known to be able to apply the planned reinforcements. During the investigations, we found material imperfections in the steel. If these are heated during welding, this could further reduce the structural safety of the bridge.
On Monday 8 November employees of Savera IJssel bridges and Rijkswaterstaat therefore started a welding test to investigate the risk in practice. We expect this welding test to be completed by the end of 2021. We will then incorporate the results in the final implementation design.
Comprehensive safety plan and proficiency testing
The integrated safety plan required for the start of the execution phase has been approved by Rijkswaterstaat. In addition, we are currently busy with the required proficiency tests at the Hollandia Services yard. With these we are testing the welding procedures and expertise of the welders who will soon be working on the IJssel bridges.
Explanation two-phase process
This renovation project is a pilot within the programme ‘Towards a Vital Infrastructure Sector’. In this programme, Rijkswaterstaat and private parties are committed to a transition to an infrastructure sector that is sustainable and innovative, financially healthy and where the risks inherent in infrastructure projects are properly managed. The IJssel bridge renovation project is one of the projects in which experience is gained with the two-phase process. In phase 1, Rijkswaterstaat and Savera IJssel bridges jointly produce the design, whereby uncertainties are removed by, for example, additional research. On the basis of the design, the definitive price is agreed with a risk profile that is acceptable to both parties. Then, in phase 2, the project is actually carried out jointly.