Vedder Bridge Emil Anderson

A unique launch for the new Vedder Bridge

Chilliwack steel arch bridge is the first to be launched using the kingpost method
Tuesday, August 14, 2018

In April, 2016 the City of Chilliwack awarded the Vedder Bridge Replacement Design-Build Project to Emil Anderson Construction. The Vedder Bridge project replaces the existing two-lane steel thru-truss bridge which was constructed in 1947. The Vedder Bridge has served as a critical link between Chilliwack and Cultus Lake/Yarrow for well over a century. The new steel arch bridge provides increased clearance above flood waters, have wider travel lanes and shoulders along with two multi-use pathways to accommodate pedestrians and cyclists.

As part of the design-build team with Emil Anderson Construction Inc., Klohn Crippen Berger provided the structural, geotechnical, hydrotechnical engineering and construction engineering services for the new Vedder River Bridge and for demolition of the existing bridge over the Vedder River.

The City of Chilliwack awarded the project based on a combination of pricing and technical merit in which aesthetics was heavily weighted. The project objectives included an innovative financial and technical solution for designing and constructing the bridge, minimal disruption to the surrounding community, environment and road/utility network.

The project also included an upgrade of the approaching roads and a new roundabout intersection on the north end to provide greater capacity and improve safety.

The new 80m long Vedder River Bridge has two spans with a 60 m steel tied arch main span with hanger rods in a “ray” arrangement. The longitudinal tie girders for the arch are comprised of steel rectangular “box” sections which connect the ends of the arches, and then continue through the 20m south side span as supporting girders. The bridge was fabricated in Delta at Supreme Steel’s Canron facility.

A fundamental component of the team’s strategy for replacement of the Vedder Bridge was to construct the new bridge on land and launch the bridge into place over the river. Launching of bridges into position is not uncommon. What is unique about this particular bridge launch is that the bridge is an arch, and the arch structure does not have the strength on its own to be cantilevered 60 metres without support on one end. To enable launching of the arch bridge, a “king post” support system was used.

The Vedder Bridge is the world’s first steel arch bridge to be launched using the kingpost method. In-river works were undesirable due to fisheries windows schedule limitations and sensitive environment. A “kingpost” and cable support system was developed to support the arch during the launch of the new bridge. The kingpost system used the precast panels, which would later be used to form the bridge deck, as large counterweights. The continuous south side span tie girders also functioned as the ”launching nose” extension required for launching. The same system was then re-used to “de-launch” the old bridge for demolition.

The launch took place in April 2017, taking more than seven hours to reach the south pier. The bridge was completed in August 2017. The design build project delivery method offered a unique opportunity for the project team to develop a cohesive and efficient bridge design package for the client.

Klohn Crippen Berger earned a 2018 Award for Engineering Excellence – Merit from the Association of Consulting Engineering Companies of BC in the Transportation & Bridges category for this project.

Leave a Reply

Your email address will not be published. Required fields are marked *