Mass Gravity Retaining Walls
2016
Cardiff, Wales
Welsh Government
Dawnes Construction Holdings
Capita
East Bay Link
FlexMac DT temporary structure
Backfill placement behind the structure
Elevation of the Temporary Structure
Problem
The East Bay link is a new duel carriageway in the Welsh capital that will add better transport links to the East of the city. The project connects Ocean Way, Cardiff to the Queens Gate roundabout. This new route will mean there is now a continuous route from the M4 into the popular Cardiff Bay. To form such a link road a low embankment and a series of viaduct structures were needed The approximate cost of the project was around £27.3 million.
Due to the requirement of an embankment onsite, Dawnus Construction looked in Maccaferri’s direction to come up with a temporary retaining solution that would be able to cope with onsite construction traffic. This had to be a temporary solution before the main retaining wall which would be installed towards the end of the project.
Solution
Maccaferri worked alongside Dawnus Construction Holdings to come up with a temporary work structure. Maccaferri suggested the use of FlexMac DT which is used for flood protection works to raise embankments and provide buttressing support for temporary works.
FlexMac DT is made of hexagonal double twisted wire mesh and vertical steel rods reinforce the mesh, the unit is lined with a non-woven geotextile. The unit can be filled with many different fill types, mainly we try to use locally sourced materials to reduce carbon footprint. This project used Type 1 Slag material recycled from the nearby steelworks and consisted of approximately 175m3 of material to fill the Flex Mac DT units to create a length of 77m.
This temporary retaining wall enabled the insertion of the long-term retaining wall system, MacWall®; this segmental blockwork retaining wall system combines the aesthetics of masonry walls with the engineered reassurance of reinforced earth. Segmental block retaining walls (“SRW”s) are increasing in popularity due to their ease of construction, cost-effectiveness and versatility.