Length of Slip Plane given Shear Strength along Slip Plane Calculator

Length of Slip Plane Formula:

\[ L = \frac{T_f - (W \times \cos(\theta) \times \tan(\phi))}{c} \]

Shear Strength of Soil (Tf):

Weight of Wedge (W):

Slope Angle (θ):

Angle of Internal Friction (φ):

Cohesion in Soil (c):

Safety Factor (±5%):

Length of Slip Plane (L):

Length with Safety Factor (±5%):

1. What is Length of Slip Plane Calculator?

Definition: This calculator determines the length of a potential slip plane in soil based on shear strength parameters.

Purpose: It helps geotechnical engineers assess slope stability and potential failure surfaces.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ L = \frac{T_f - (W \times \cos(\theta) \times \tan(\phi))}{c} \]

Where:

\( L \) — Length of slip plane (meters)
\( T_f \) — Shear strength of soil (Pascals)
\( W \) — Weight of soil wedge (kg)
\( \theta \) — Slope angle (degrees)
\( \phi \) — Angle of internal friction (degrees)
\( c \) — Cohesion in soil (Pascals)

Explanation: The formula calculates the length where shear stress equals shear strength along a potential failure plane.

3. Importance of Slip Plane Calculation

Details: Accurate slip plane length estimation is crucial for slope stability analysis, retaining wall design, and landslide prevention.

4. Using the Calculator

Tips: Enter all required parameters including safety factor (±5%). Angles should be in degrees. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a slip plane?
A: A slip plane is a potential surface along which soil mass may fail due to shear stress exceeding shear strength.

Q2: How is safety factor applied?
A: The safety factor (±5%) provides a margin of safety by increasing the calculated length by the specified percentage.

Q3: What are typical cohesion values?
A: Cohesion varies from 0 kPa for loose sand to 50+ kPa for stiff clay.

Q4: How do I determine angle of internal friction?
A: This is typically measured through direct shear or triaxial tests in geotechnical labs.

Q5: When would this calculation be used?
A: For slope stability analysis, embankment design, and assessing potential landslide risks.