Natural slope reinforcement method

Needs Address

The need to reduce vulnerability of slopes that risk landslide or surface layer collapse

Adaptation effects

Stabilizes slope and contributes to disaster prevention and reduction while also preserving existing trees and landscape

Overview and Features

• This slope reinforcement method is designed to stabilize a bank or slope by installing a system of metal bars or other rod-shaped reinforcing components, making use of the tensile resistance and torque resistance of the components. 
• The basic design of this slope reinforcement method includes a reinforcing component (lock bolt), grout, and pressure-bearing plates.
  
  Figure: Basic structure of slope reinforcement method
  Source: Non-Frame Research Institute
• By modifying the bank, this method stabilizes the slope, restricting movement of an unstable soil mass. It exploits the combined effects of components inserted into the bank, including tensile reinforcement, shear reinforcement, and torque reinforcement.

Cost

Using typical products, the cost is in the range of about 30,000 yen per square meter (Non-Frame method below costs about 26,000 yen per square meter). 

Ease of maintenance

Regular inspections are needed to check for lifting of the pressure-bearing plates, and abnormal tension or loosening of the wires, etc. 

Technology performance

This technology can be used to prevent surface soil collapse up to a maximum thickness of about 3 meters. 

Considerations

This technology is difficult to apply in the case of a rock slope with many fissures or where there is the risk of massive slope collapse. Caution is also necessary on slopes where the groundwater level is close to the surface, where the ground has no cohesion, or in cohesive soft clay ground.

Co-benefit, suitability for developing countries

• Installation can be done quickly as the construction method is easy and materials are light in weight. 
• Because of the net-like structure, the slope can be stabilized with minimal ground cutting or tree clearing, while also preserving the natural environment.

Information Resources

Non-Frame Research Institute: 
http://www.non-frame.com/about/index.html