Soil Nailing / Slope Stabilisation
Riddell Road Slope Stabilisation
A foreshore cliff in Glendowie needed stabilising above an existing palisade retaining wall — tight access, undulating ground, and drilling angles that had to thread past the wall's elements. Geo Mana delivered self-drilling soil nails, tensioned MacMat R mesh fixed cleanly into the wall, and horizontal drainage, all from rope access. 1,296.5m of drilling, ~750m² of mesh, 150+ galvanised pins — and every proof-load test passed on the first attempt.
The challenge
What made this difficult
A foreshore cliff section on Riddell Road needed stabilising after historic ground movement and ongoing erosion. The slope sat directly above an existing palisade retaining wall, so every part of the work — drilling angles, mesh termination, crew positioning — had to respect the structure already in the ground. On top of that, every soil nail had to be tested and verified to engineering specifications before sign-off.
Specific issues
Soil nail drilling angles had to avoid existing palisade wall elements while still meeting the design requirements
Undulating ground with limited access, demanding disciplined rope access positioning
A clean termination detail was needed where the mesh meets the palisade wall
Full verification and proof-load testing required for engineering sign-off
The response
- 01
Completed the soil nailing with self-drilling methods suited to the tight access and variable ground conditions
- 02
Worked from rope access with Platypus anchors for safe, precise positioning on the slope face
- 03
Installed and tensioned MacMat R mesh across the stabilisation footprint, mechanically fixing the mesh line into the palisade wall for a clean finish
- 04
Installed horizontal drainage across the stabilised area to manage groundwater
- 05
Proof-load tested every soil nail to the engineer's requirements — all tests passed
Spec snapshot
The numbers on record
- 01Drilling: 1,296.5m
- 02MacMat R mesh: ~750m²
- 03Galvanised steel pins: 150+
- 04Horizontal drainage installed across the full stabilised area
The outcome
Work that holds up.
This project shows what an integrated slope solution looks like when it has to work around an existing structure. The team delivered soil nailing, flexible mesh facing, and drainage as one system, threading drilling angles past the palisade wall elements and mechanically fixing the mesh line into the wall for a clean, deliberate interface between old and new. All works were delivered safely from rope access on undulating ground with limited plant access. Every soil nail was proof-load tested to the engineer's requirements, and every test passed on the first attempt. With 1,296.5m of drilling, around 750m² of MacMat R mesh, and horizontal drainage across the full footprint, the slope above the wall is stabilised, drained, and verified to specification.
- Self-drilling soil nails
- MacMat R mesh
- Platypus anchors
- Rope access
- Horizontal drainage
- Proof-load testing
- Crane operations
From the face
How it looked on site
Actual project photography
Your ground
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