Length of Slip Circle given Factor of Safety in Absence of Flow Net Calculator

Length of Slip Arc Formula:

\[ L' = \frac{(fs \times \Sigma T) - (\Sigma N \times \tan(\phi'))}{c'} \]

Factor of Safety:

Sum of all Tangential Component:

Sum of all Normal Component:

Effective Angle of Internal Friction:

Effective Cohesion:

Length of Slip Arc (m):

1. What is Length of Slip Circle Calculator?

Definition: This calculator determines the length of the slip circle arc in slope stability analysis when flow net data is not available.

Purpose: It helps geotechnical engineers assess slope stability by calculating the critical slip surface length.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ L' = \frac{(fs \times \Sigma T) - (\Sigma N \times \tan(\phi'))}{c'} \]

Where:

\( L' \) — Length of slip arc (meters)
\( fs \) — Factor of safety
\( \Sigma T \) — Sum of all tangential components (N)
\( \Sigma N \) — Sum of all normal components (N)
\( \phi' \) — Effective angle of internal friction (degrees)
\( c' \) — Effective cohesion (Pa)

Explanation: The formula balances the resisting forces (cohesion and friction) against the driving forces (tangential components).

3. Importance of Slip Circle Length Calculation

Details: Accurate calculation helps identify potential failure surfaces and ensures proper slope design to prevent landslides.

4. Using the Calculator

Tips: Enter all required parameters. The ±5% indicates typical measurement accuracy ranges for these parameters.

5. Frequently Asked Questions (FAQ)

Q1: What is a slip circle?
A: A slip circle is a theoretical circular failure surface used in slope stability analysis.

Q2: When is this calculation used?
A: When detailed flow net data is unavailable but basic soil parameters are known.

Q3: What affects the length of the slip circle?
A: Soil strength parameters (cohesion and friction angle), slope geometry, and loading conditions.

Q4: How accurate is this method?
A: It provides a reasonable estimate (±5%) when proper soil parameters are used.

Q5: What if I get a negative result?
A: Check your inputs - negative values may indicate invalid parameters or calculation errors.