Soil nailing uses grouted, tension-resisting steel elements (nails) to reinforce in situ soils and creating a gravity retaining wall for permanent or temporary excavation support.

Common uses

• Stabilise slopes and landslides
• Support excavations
• Repair existing retaining walls

Process

Soil nail walls are generally constructed from the top down. Typically, soil is excavated in three to six feet deep stages. After each excavation stage, near-horizontal holes are drilled into the exposed face at typically three to six foot centres. Tension-resisting steel bars are inserted into the holes and grouted in place. A drainage system is installed on the exposed face, followed by the application of reinforced shotcrete wall facing. Precast face panels can also be used. Bearing plates are then fixed to the heads of the soil nails. This installation process is repeated until the design wall depth is reached. The finished soil nails then produce a zone of reinforced ground.

Advantages

• Equipment is small enough to use in areas with restricted access
• Often a more cost effective and faster solution for excavation support
• Can be installed from crane-suspended working platforms for existing steep slopes, such as bluffs or existing retainng walls
• Allows excavation to start at the same time as the shoring system is being installed
• Quality assurance
• Keller has been installing and developing soil nailing techniques for many years. We use specialised equipment and experienced crews and employ strict quality control measures to ensure uniform and consistent results.

Grouted Nails

Grouted soil nailing method

In this method, the holes are drilled in slope face and walls. Nails are then inserted in the holes and after that holes are filled with grouting materials like concrete, shotcrete etc. The diameter of nails ranges from 100 mm to 200mm and spacing between nails are 1.5 m.

Rock Anchoring (Active & Passive Anchors)

The bars are bonded to the earth with high strength grout composed of cement, sand or other materials Anchoring the rock in this manner helps resist lateral thrust on the walls, stabilizes slopes and strengthens masonry. Pre-stressed rock anchor our inserted at a 45 degree angle and are used to protect shore piles. Passive anchors are drills at a 90 degree angle (vertically) on a raft of PCC cement. The main purpose of rock anchoring is to stabilize the foundation of the construction and avoid its movement. Several factors such as hydrostatic pressure, wind loads, seismic activities among others, can induce an uplifting force on the foundation. It can endanger the constructional integrity of the structure.