What is Slope Stability and Why Does it Matter?

Slope stability refers to how much stress a slope can endure before collapsing. This information matters to civil and geotechnical engineers involved in planning construction for roads, dams, embankments, and other excavated slopes, as failing to understand slope stability could result in landslides, unwanted movement, or injury to both property and individuals. A slope stability analysis (sometimes referred to a Landslide Hazard Analysis) is performed to assess soil mechanics and plan for future stabilization efforts.

Slope Stability Analysis

Depending on the project, a slope stability or landslide hazard analysis may be part of your site investigation. This important evaluation helps to reveal potential indicators for slope failure, including:

  • Topography: Measuring the slope’s height differences at all points in the terrain
  • Material Strength: Determining which building methods will be appropriate for the proposed slope
  • Soil Water Content: Planning for proper irrigation and stormwater mitigation around the slope
  • Vegetation: How the area’s trees, shrubs, and grass contribute to overall stability

There are several different methodologies for conducting slope stability analysis, with both 2D and 3D testing. Both approaches may be used for the most thorough insight, especially when the slope involves complex geometry or significant differences in slip surface.

Understanding how natural forces behave allows geotechnical engineers to adjust plans as necessary, ensuring the slope can withstand long-term pressures, climate conditions, and geological events without movement or failure.

Slope Stabilization Methods

Should concerns arise during the slope stability analysis, there are a number of slope stabilization methods available. Taking soil conditions and site constraints into account, geotechnical engineers may propose:

  • Earthwork: Steeper inclines are more susceptible to failure, so in order to keep projects moving, engineers can work on flattening, buttressing, or benching the slope appropriately.
  • Drainage alterations: Water is the biggest cause of slope slippage, especially during flash floods or heavy weather patterns. Improvements could include diverting water through catch basins or sealing tension cracks, as well as removing excess drainage through subsurface drains.
  • Structural changes: Engineers have devised many ways to improve slope stability with structural enhancements such as tie backs, reticulated micropiles, soil nailing, retaining walls, drafted shafts, or mechanically stabilized earth.

It is not uncommon for one or multiple slope stabilization methods to come into play for the same project, as there are typically many factors that contribute to slope stability.

Evaluate Slope Stability and Landslide Hazards With Central Geotech

Work with Central Geotechnical Services to help prevent slope failure on your next project. Our expert team uses all the latest technology and analyses to give you a comprehensive geotechnical report of your site. Contact us for more information.