This project involved the design and construction of three retaining walls to remediate slips and increase the road width. Hiway GeoStabilization’s design involved installation of micropiles and construction of a reinforced concrete footing. Once the footing was completed Hiway GeoStabilization installed soil nails and rockfall mesh netting on the embankment. A GCS® wall was then constructed and finished with a masonry block facing. Construction works were undertaken under Level 1 Stop/Go traffic control, as the road was too narrow to enable sharing of a single lane of traffic with construction machinery.
This project involved extensive testing and quality control for both the soil nails and micropiles, including pull-out tests, grout UCS testing, as well as significant compaction testing of the GCS® wall backfill.
After a series of sub-tropical cyclones pounded the upper North Island in early 2017, the road infrastructure owned by Auckland Transport and managed by Broadspectrum suffered extensive damage.