Exceptional bridge piers

RMG Joint Venture

A new interchange and bridge was constructed as part of a motorway upgrade and bespoke formwork is needed to create the bridge piers.

The Goal

To build a new interchange while causing the least disruption possible
The A1 arterial road in the north of England is being upgraded to a motorway to relieve traffic congestion in the area. In the Leeds region, several bypass roads are under construction including the Holmfield Interchange. The new interchange includes a bridge with exceptional and unique bridge piers. However, construction needed to progress without disrupting traffic on the adjacent roads.

The Project

Summary:
The bridge piers were constructed to a high specification despite the requirements to minimise disruption to local traffic.

Challenge:
Keeping the adjacent M62 open to traffic during the construction of the new bridge was the main challenge on this project. However, the demanding architectural requirements for the 22 bridge piers added an extra layer of complication.

The Solution

Meeting demanding requirements
The new interchange would have various flyovers at different levels. Therefore, the 22 piers had varying heights of between 6m and 17m. In addition, the form and surface finish of the unusual, Champagne cup-shaped piers had strict requirements.

A series of vertical features were required on each pier, as well as a smooth, architectural finish. The ideal solution needed a formwork system which was steplessly adjustable in height, could handle large concrete pressures, and also met the high safety requirements. It also had to guarantee an outstanding concrete finish, showing the features and curved areas of the piers.

The contractor chose the MEVA Mammut standard large formwork panels, combined with some custom-built steel parts with pre-bent alkus facing sheets. The stems of the piers – which for some piers reached up to a height of 11.5m – were poured in the first concreting cycle. The wineglass shaped pier heads were poured in a second cycle. The vertical features of each pier were achieved by screwing shaped timbers onto the forming face of the Mammut formwork.
Flexible climbing scaffolds

Constructing Bridge Piers using Special Formwork on one of the UK’s major roads

To create the wineglass-shaped pier heads, KLK 230 climbing scaffolds served as support for the formwork and, at the same time, as a safe working platform. Since the pier heads had different gradients, two curved headwall formwork units were set up independently at different heights for every bridge pier. Using the KLK scaffolds meant that the adjacent roads could be kept open without having to close areas for falsework and shoring.
Innovative solutions for any situation
The formwork for the piers – which were located in the central reservation between the lanes – required a special kind of bracing. A conventional bracing system would have led to narrow lanes during the construction process, which would have caused too much disruption to traffic.

MEVA were able to tailor a perfect solution with standard rentable parts. The wind loads were transferred by two Space shoring towers, which were also positioned in the central reservation. The formwork and bracing – which consisted mainly of standard parts with the purpose-built additions, as well as all necessary safety accessories – ensured a fast and easy to assemble system for use in this situation.

The Outcome

The contractor was extremely satisfied with the formwork systems and the concrete finish obtained. The project was well planned and, from spring 2006 on, has guaranteed an undisturbed flow of traffic from the South of England to the North and Scotland.