A two-tier gabion terrace wall installation along the edge of a SuDS pond at a new housing development on the outskirts of Sunderland

Requirement

Phi Group was approached by BDW North East to design, supply and install two tier gabion terrace walls. The terraced gabion walls comprised  a 2m wall at the lower level and 2.5m at the upper level with lengths of 170m and 125m respectively.

Challenges

There were multiple challenges for this project, in particular the sequencing of the construction of the terrace gabion walls with the SuDS pond at the lower level. It was originally proposed that the lower wall be built from the crest of the wall, with stockpiles of material located at the crest of the upper slope (crest of the upper proposed terrace). This proposal required cutting of a slope and then placing the removed material back again.

Solution

To prevent any unnecessary cutting and removal of material, it was agreed that it would be more efficient to install the maintenance road at the toe of the lower terrace wall, and then construct the lower gabion wall from below. The upper terrace would then be constructed from the crest of the upper wall.

This project was a great example of flexibility of approach by both Phi Group and Sirius Civils.