Moment of Resistance given Unit Cohesion Calculator

Resisting Moment Formula:

\[ M_R = c_u \times L' \times d_{radial} \]

Unit Cohesion (c_u):

kPa

Length of Slip Arc (L'):

Radial Distance (d_radial):

Tolerance:

Resisting Moment (M_R):

1. What is Resisting Moment?

Definition: Resisting Moment is the moment (or torque) that counteracts the applied moment or load that tends to cause rotation or failure in a soil mass or structure.

Purpose: It helps geotechnical engineers analyze slope stability and design retaining structures.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ M_R = c_u \times L' \times d_{radial} \]

Where:

\( M_R \) — Resisting Moment (kN·m)
\( c_u \) — Unit Cohesion (kPa)
\( L' \) — Length of Slip Arc (m)
\( d_{radial} \) — Radial Distance (m)

Explanation: The resisting moment is calculated by multiplying the soil's unit cohesion by the length of the potential failure surface and its radial distance from the center of rotation.

3. Importance of Resisting Moment Calculation

Details: Accurate calculation of resisting moment is crucial for assessing slope stability and preventing landslides or structural failures.

4. Using the Calculator

Tips: Enter the unit cohesion in kPa, length of slip arc in meters, radial distance in meters, and optional tolerance percentage (default ±5%).

5. Frequently Asked Questions (FAQ)

Q1: What is unit cohesion?
A: Unit cohesion is the shear strength property of a soil that is solely attributed to cohesive forces between soil particles.

Q2: How is the slip arc length determined?
A: The slip arc length is typically determined through geotechnical analysis of potential failure surfaces.

Q3: What does radial distance represent?
A: Radial distance is the distance from the center of rotation to the point where resistance is being calculated.

Q4: Why include a tolerance percentage?
A: The tolerance accounts for uncertainties in soil properties and measurement inaccuracies.

Q5: What are typical values for unit cohesion?
A: Cohesion values vary widely: clays (10-200 kPa), silts (5-50 kPa), sands (0 kPa - cohesionless).