Safety of heritage bridges and wharf cellars

How safe are our heritage bridges and wharf cellars? Can they cope with the current traffic volumes? How much has their structure weakened since they were built? Witteveen+Bos has been commissioned by the municipalities of ‘s-Hertogenbosch and Utrecht to assess the structural safety of inner-city traffic bridges and wharf cellars. We are working alongside partner firms Iv-Infra, Royal HaskoningDHV, Nebest and Antea.

's-Hertogenbosch and Utrecht both have large numbers of masonry structures over which urban traffic passes. These include bridges, overpasses and Utrecht’s very familiar wharf cellars. Careful attention to structural safety and the state of maintenance is needed to continue using these often monumental objects safely over the decades ahead. Specifically for the bridges in ‘s-Hertogenbosch and the wharf cellars in Utrecht, we are carrying out a range of operations to determine their structural safety. We advise on measures to strengthen the structure where this is called for.

Witteveen+Bos is conducting targeted condition and structural inspections to assess the structural safety. We are also conducting material and residual-life tests and preparing computational structural assessments (including NEN 8700 series and CROW-CUR Recommendation 124). Where necessary we determine measures that can extend the lifespan, and we furnish an estimate of the costs. Using 3D calculation software allows a better use of (hidden) structural capacities, thereby often avoiding the need for reinforcements. All this occurs in an open dialogue and in good cooperation with both municipalities and the other project partners. The experiences and lessons learned in the projects are shared openly within the collaboration. Among these, an approach was developed for the assessment of masonry arch constructions in the projects in 's-Hertogenbosch, which was then applied and developed further in assessing the wharf cellars in Utrecht. This lets us arrive jointly at suitable repair measures with full preservation of the monumental values.

The need has gained momentum over recent years both in the Netherlands and abroad, for a clear view of the structural safety and state of maintenance of existing civil engineering works. A large number of objects are nearing the end of their (technical) lifespans. The scale of the ‘Replacement and Renovation Project’ requires all the parties involved to pool their knowledge and experience. Witteveen+Bos will continue to rise to the challenge in 2021. Together we can keep our civil engineering structures safe and usable for decades to come.