Resisting Moment given Radius of Slip Circle Calculator

Resisting Moment Formula:

\[ MR = r \times ((c_u \times L') + (\Sigma N \times \tan(\phi_i))) \]

Radius of Slip Circle:

Unit Cohesion:

Length of Slip Arc:

Sum of all Normal Component:

Angle of Internal Friction:

rad

Resisting Moment (kN·m):

1. What is Resisting Moment given Radius of Slip Circle?

Definition: This calculator computes the resisting moment in a slope stability analysis based on the radius of the slip circle and soil properties.

Purpose: It helps geotechnical engineers evaluate the stability of slopes and embankments by calculating the moment that resists sliding.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ MR = r \times ((c_u \times L') + (\Sigma N \times \tan(\phi_i))) \]

Where:

\( MR \) — Resisting Moment (kN·m)
\( r \) — Radius of Slip Circle (m)
\( c_u \) — Unit Cohesion (Pa)
\( L' \) — Length of Slip Arc (m)
\( \Sigma N \) — Sum of all Normal Components (N)
\( \phi_i \) — Angle of Internal Friction (radians)

Explanation: The resisting moment is calculated from both cohesive and frictional components of soil strength along the potential failure surface.

3. Importance of Resisting Moment Calculation

Details: Accurate calculation of resisting moment is crucial for determining the factor of safety against slope failure and designing appropriate stabilization measures.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. The calculator accounts for ±5% uncertainty in input values. All values must be ≥ 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a slip circle in slope stability analysis?
A: A slip circle is a hypothetical circular failure surface along which slope failure might occur, used in limit equilibrium analysis methods.

Q2: How do I determine the angle of internal friction?
A: It's typically determined through laboratory tests like direct shear or triaxial tests on soil samples.

Q3: What if my soil has no cohesion (c=0)?
A: Simply enter 0 for unit cohesion - the calculation will consider only the frictional resistance component.

Q4: Why is the result in kN·m?
A: Resisting moment is typically expressed in kN·m in geotechnical engineering practice for convenient magnitude.

Q5: How does radius affect the resisting moment?
A: The resisting moment is directly proportional to the radius - larger slip circles generally have greater resisting moments.