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Introduction

There are a number of techniques used in civil engineering practice to achieve slope stabilization, including but not limited to:

• Soil nailing
• Retaining walls
• Anchored blocks
• Gabions
• Micropiles
• Plate piles
• Grid beams
• Wood logging
• Reinforcement with geogrid or other geosynthetics
• Shotcrete covering
• Reinforced soil
• Recycled plastic pins

Some of the aforementioned are described and examples are given in the following sections.

Soil Nailing

In soil nailing, stabilization is achieved through the use of steel bars (nails), which help provide support to the slope and/or infrastructure. The nails interact with the ground and allow for a better stress distribution. The nails are installed to depths of 30m. This method can be used for slopes 12-30m high.

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Figure 2.13. Applications of soil nailing for the stabilisation of slopes.

Retaining Walls

Retaining walls are rigid structures used to prevent slopes (typically artificial slopes) from sliding. Depending on the resistance mechanism, retaining walls are divided into:

• gravity walls,
• piling walls,
• cantilever walls, and
• anchored walls.

Figure 2.14.  Different types of retaining walls.

Anchored Blocks

Blocks are strategically placed across the slope to resist the movement of sliding soil. Each block is stabilised by anchors. To prevent sliding of smaller particles, a steel mesh can be installed.

Gabions

Gabions are cages or boxes filled with aggregates or soil. They are used to provide stability through their weight. Their resistance mechanism is similar to that of reinforced concrete retaining walls.

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Figure 2.15. Gabion wall applications: (a) Reinforced earth with gabions supporting a multilane roadway, Sveti Rok, Croatia,
(b) gabion wall of cliff reinforcement, (c) bridge abutment with gabions.

Micropiles

Micropiles are concrete beams sometimes anchored which are used to achieve stabilization of the soil. The micropiles are installed as typical piles, but their function is not the transference of overburden from a structure safely to the soil, but to keep layers of soil with different properties together (Fig. 2.16a). The balancing mechanism through a micropile is shown in Fig. 2.16b.

Figure 2.16 . (a) Micropiles used to stabilise a slope, (b) balancing mechanism through a micropile.

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