1. CONSTRUCTION OF SOIL NAILING WALLS
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Student’s Name

2. Contents Subsoil considerations Design consideration
Construction considerations
Construction and installation steps
Advantages
Disadvantages

3. Subsoil Considerations
Favorable Conditions
Soil should be stiff or hard with fine grains
Grains should have low plasticity
Soil should have natural cohesion provided by either capillary water of natural cementation
Subsoil with weathered rock should be uniformly weathered

4. Subsoil Considerations
Unfavorable Conditions
Dry and poorly grained soils
Soils lacking natural cohesion or cementation
Soil with a lot of ground water
Soil with a lot of cobbles and boulders
Soil that is not uniformly weathered
Highly corrosive soils

5. Design Considerations
Drainage considerations
Use of geo-composite drain strips along the excavation walls to allow water to be discharged through weep holes at the bottom of the wall
Use of drain pipes to control ground water pressure.
Designing ditches behind the walls to prevent surface water from infiltrating behind the walls

6. Design Considerations
Other considerations
They should be designed to resist damage caused by frost action by increasing thickness of soil wall be using porous material
The wall should be designed in a way that it can withstand both external loads such as highways and the weight of the temporary facing.

7. Construction Considerations
The state of the construction material should be in good physical conditions and as per the design specification
Check to ensure the excavation walls are stable and that the nails are properly installed with the right length size and spacing
Check to ensure the completed soil wall is not tampered with during excavation of the next phase

8. Construction Considerations
The contractor should ensure that the soil nail drilling is done as per the specifications
The amount of time the drill holes remain open to avoid caving
Materials are properly handled to avoid damages
Ensure nails are properly grouted in the grouted column with no gaps left

9. Construction and Installation Steps
Excavation is done to a level the walls can support themselves for 2 days. It is made about 6feet and wide enough for equipment
Drilling the nail holes according to the design specifications
Installing the nails using centralizers together with pipes filled with grouting cement. Geo-composite walls are also installed in this phase.

10. Construction and Installation Steps
4. Construct temporary facing to support the open cut soil using a reinforced layer of welded wire mesh between the facing thickness
Construction of subsequent levels by repeating steps 1- 4
Finally construct a permanent facing using reinforced concrete and fabricated panels

11. Advantages of Soil Nail Walls
Construction advantages
Doesn’t disrupt the flow of traffic as compared to other methods
It provides a less congested excavation bottom
It has a rapid construction schedule
The design can be easily adjusted without creating safety issues

12. Advantages of Soil Nail Walls
Performance
Resultant wall are very flexible
The structures have very small deflections
The walls can withstand seismic activities
Cost
Overall cost is lower than other methods
Uses cheaper materials such as shortcrete

13. Disadvantages of Soil Nail Walls
Can be implemented by highly trained and experienced contactors only.
It is not favorable in areas with a lot of ground water
The presence of different utilities pose a challenge in terms of inclination and length of the soil nails during construction in the upper rows

14. END