Repairing a slope without knowing why it failed often wastes money. A proper landslide investigation finds the mechanism first, and slope stability analysis then tests which solution will work.
Why slopes fail
- Water: heavy rain, seepage and blocked drainage
- Geometry: steep cuts and loss of support at the toe
- Material: weak, weathered or clay-rich soil and rock
- Structure: rock joints that dip out of the slope
- Loads: fill, buildings and traffic near the crest
How the investigation works
- Survey: drone or LiDAR mapping of steep, unsafe areas.
- Geological mapping: rock type, joints, cracks and seepage.
- Geophysics: ERT and seismic refraction help define depth and water zones.
- Boreholes: samples and direct data on the slip surface.
- Laboratory tests: strength of slope materials.
- Analysis: stability under dry, wet and, where relevant, seismic conditions.
What slope stability analysis gives you
The analysis produces a factor of safety, which compares resisting forces with driving forces. Engineers use it to compare the existing slope with each proposed solution, so the money goes to measures that make a real difference.
Common protection measures
- Surface and subsurface drainage
- Regrading or benching of the slope
- Retaining structures
- Soil nails, rock bolts and anchors
- Rockfall mesh and barriers
- Vegetation for surface erosion
Indian Standards such as IS 14680 give guidance on landslide control. See our landslide protection service.
FAQ
What is a factor of safety in slope stability?
It is the ratio of the forces resisting failure to those causing it. A value above 1 means the slope is calculated to be stable, and the required margin depends on the project.
Why is drainage so important?
Water adds weight and reduces soil strength, so controlling it is often among the most effective measures.
Can a landslide be investigated while it is still moving?
Yes, but with care. Drone mapping and geophysics are useful because they reduce the need for people on unsafe ground.
Talk to our team
Have an unstable slope? Call +91 98718 04288, email contact@geowingseng.com or send us the location and photos.
