22 May 2019
sponsored by RIFT R&D
S22 Bearing Replacement (QEII Bridge) - submitted by Jackson Civil Engineering
The QEII Bridge at Dartford opened in 1991. Today it carries over 75,000 vehicles every day, and forms a critical part of the capital’s infrastructure. The structure has always been subject to a substantial maintenance regime, however, now in its 28th year, there are certain elements of the bridge that require long-term, innovative maintenance solutions to sustain this nationally-significant piece of infrastructure.
There are 50 piers on the bridge, with five bearings at each pier head – a total of 250 bearings on the structure. Since 1991, the bearings have been subject to temporary maintenance, but now there is a requirement to replace some of the bearings in their entirety. Due to the size of the QEII Bridge, proprietary jacking systems were too small, and the hydraulic systems, which use collars or shims to lock off the hydraulics once jacked, were deemed too risky due to the abnormal loading patterns they can put on the structure, and the potential for failure in situ.
In addition, conventional bridge bearing replacement schemes use temporary jacking systems that usually only allow for a short working window, and require a full closure of the structure. With an extensive schedule of bearings to replace over the coming years, it was imperative to find a solution that caused as little disruption as possible.
Jackson used a really simple and inherently safe solution to a problem that has the potential to improve millions of journeys over the course of the coming years - not only on the QEII Bridge but on numerous structures across the UK highway network.
The use of elastomeric bearings has not only increased the maximum working window on the QEII Bridge by 600% (from 12 hours to 72 hours), it has also facilitated this work under live traffic, vastly reducing the number of closures required to complete the bearing work.
Their team has worked collaboratively with parties across the supply chain to develop the design, prove the methodology, and put it all into practice on one of the busiest sections of motorway in the UK.
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The SECBE 2019 Innovation Award is sponsored by RIFT R&D.