The near vertical MacWall “Vertica” segmental retaining wall was designed by geo-technical engineers, Maccaferri, as a mass gravity structure to maximise land gain behind it and land loss in front of it. Because of its minimal footprint in contrast to conventional retaining walls, the roots of existing trees and shrubs were relatively undisturbed enabling all of them to be retained.

 

The 125 metre-long structure - which is six metres at its tallest point - was installed Joe Kerlin Site Services on behalf of main contractor, McLaughlin & Harvey.

 

Welcoming completion of the project, Liam Clarke, McLaughlin & Harvey’s contracts manager for the site said:

 

“In addition to the trees, another major concern was that the retaining wall would be supporting a busy access road through the university campus. Closing the road was not an option so the solution had to be flexible and fast to construct. The MacWall retaining wall gave us that solution.”

 

MacWall Vertica is a dry built, segmental system made up of concrete facing blocks that usually work together with geo-grids and compacted back-fill to form a highly efficient, engineered retaining wall. The wall is installed by hand and does not require concrete foundations, making it ideal for situations where speed of installation in space-restricted areas is required.

 

At the University of Ulster site, the space constraints and ground conditions were such that traditional geogrid soil reinforcement techniques could be replaced with a ‘dry-mix’ concrete backfill to the wall. This formed a more slender structure, necessary to minimise disruption to the existing trees.