Soil Nailing Installation

Soil nailing uses multiple types of materials consisting of steel, fiberglass and even hollow bars made up to penetrate the surface and stabilise unstable ground conditions. Soil nailing provides strength and retention to soft soil and also promotes regrowth in those areas.

At Ground Stabilisation Systems, we only use the highest quality soil nails and utilise the latest innovations in ground stabilisation for our clients. Detailed investigation and planning, along with the latest technology, ensures every project provides a stable, long term solution to even the most demanding slopes and unstable sites.

Soil nailing equipment can be small enough to easily negotiate areas with restricted access. For existing steep slopes, the soil nails can be installed from Telehandlers/EWP’s and crane-suspended working platforms and even by means of position drills with helicopters. Soil nails can also be installed directly beneath existing structures adjacent to excavations and used to stabilise retaining walls or existing fill slopes.

Care should be exercised when applying the system underneath an existing structure. Ground Stabilisation Systems uses extensive 3D modelling to avoid conflicts between soil nails and other earth retention systems on complex projects that involve the use of multiple techniques and to ensure the safety of buried utilities.

Consideration

Some investigation and analysis are required to determine whether soil nail installation is the right solution to your ground stabilisation problems. Considerations include:

• The condition of the ground
• The suitability of other systems like ground anchors and geosynthetic materials
• Costs and budgetary requirements.

While soil nails are versatile and can be used for a wide variety of soil conditions, Soil types like clay, glacial soils, sand, and gravel are well suited for soil nail installation. Soil nails can also be used on weathered rock so long as the weathering is even and without any weak planes.

Soil types with a high groundwater table, soft fine-grained soils, corrosive soils, loose granular soils, and ground exposed to repeated freeze-thaw action are generally not suited to soil nail installation.

For the team at Ground Stabilisation Systems, we will also need to consider the design and the capability of soil nails to complete the task at hand. These considerations include:

• Ground properties and soil type
• Nail length, diameter, and maximum force
• The inclination of the soil nails
• Vertical and horizontal spacing of the soil nails
• The strength limit i.e. where potential failure or collapse could occur
• Drainage
• Wind and hydrostatic forces.

Pros & Cons

There is a wide range of benefits to soil nail installation:

• The equipment is small enough to use in areas with restricted access. Soil nails can even be installed from crane-suspended working platforms for steep slopes like bluffs and existing failing retaining walls.
• Soil nails are a fast and cost-effective solution for excavation support. Generally, soil nail walls are more economical than concrete gravity walls and ground anchor walls. Soil nail installation is also more cost-effective for sites with remote access because the equipment required is smaller and readily mobilised.
• Soil nails are less disruptive to traffic and have a smaller environmental impact compared to other construction techniques like drilled shafts and soldier pile walls.
• Soil nail walls are flexible and can accommodate differential movements. They have also performed well during seismic events like earthquakes.

However, even the most effective system have their limitations. For soil nail installation, these include:

• Utilities behind the soil nail wall will create restrictions to the location, inclination, and length of the soil nails. This includes some kinds of communication lines like optic fibre running adjacent to the soil nails.
• Soil nails are not suited to areas where large amounts of groundwater seep into the excavation. Soil nails require a temporarily unsupported excavation face during construction.

Drainage

To reduce groundwater in a soil nailing installation project, a sub horizontal drainage system may be inserted once the nails are in place. This involves a PVC drainage pipe or synthetic drainage mat that is placed vertically between the nail heads and extends to the wall base while also connecting to a footing drain.

Drainage is often required to avoid flooding and other damage in civil engineering and construction projects.

This service is applicable to various terrains and locations.