Stability of Slopes is the Procedure of measuring and assessing how much stress a particular slope section can manage before failing.
Slopes in Geotechnical Engineering
Slopes means embankments or A slope is an inclined ground surface which can be either natural or constructed in engineering projects. Slopes are generally provided in Roadways, earthen dams, Railways, River training works, etc.. These may be fail due to earthquake, erosion, excavation, sudden draw the water table, etc. For which Slopes Stability is analysed using various Methods.
Types Of Slopes
Slopes are generally two types in Geotechnical engineering:
- Infinite Slopes
- Finite Slopes
Infinite Slopes: What is the Infinite Slopes in Soil Mechanics/geotechnical engineering?
If the Slopes represents the boundary surface of infinite soil mass and the Properties of the soil mass at similar depth below the ground surface, it is defined as Infinite Slopes. Failure of Infinite Slopes take place due to sliding and the failure surface is parallel to the Ground surface plane or slope.
Finite Slopes: What is the Infinite Slopes in Soil Mechanics/geotechnical engineering?
If the Slopes are of Finite extent bounded by top and bottom surface, it is defined as Finite Slope. Failure of the Finite Slopes take place due to Rotation and failure plane is either circular or spiral.
Causes of Slopes Failure
The failure of Slopes occur when the forces causing failure are greater than the shearing resistance. Failure of which take place due to following forces:
- Gravity Force
- Seepage Force
- Earthquake
- Erosion due to Water
- Sudden draw down the Water Table
- Excavation near the Slopes
Check Out Geotechnical Engineering in Details
Stability Analysis of Slopes
Slopes stability analysis is a static or dynamic, analytical or empirical method to measuring the stability of earth and rock-fill dams, embankments, excavated slopes, River training works, Roadways, Railways and natural slopes in soil and rock. Stability of Slopes is a condition of inclined soil mass or rock slopes to withstand or undergo movement.
The purpose of analysing is to know the causes by which slopes failure occurs, resulting in a landslide can be occurred. This is done for the purpose of stopping, slowing it down or arresting it through mitigation countermeasures.
Assumption’s in Slopes Stability Analysis
There are following assumption made in analysis of Slopes Stability:
- Slope Stability problem is a Two Dimensional Problem.
- Shear Parameters of the soil are constant along any possible slip surface.
- In Problem involving seepage of water, flow net can be constructed and the Seepage Force can be determined.
Stability Analysis of Infinite Slope
A slope that extends for a relatively long distance and has a consistent subsurface profile may be analyzed as an infinite slope. The failure plane for this case is parallel to the surface of the slope and the limit equilibrium method can be applied readily.
Let’s assume, The inside width is unity. Consider an infinite Slope AB having a slope angle of í with the horizontal, Failure of which take places along the plane CD that is at a depth z below the Surface. Considering unit length of the slope in the plane.
| Area of soil wedge ABCD = z.b.cosí Volume of soil wedge ABCD = (z.b.cosí)×1 |
