Mobilized Cohesion Calculator

Mobilized Cohesion Formula:

\[ C_m = \frac{c}{F_c} \]

Mobilized Cohesion (Pa):

1. What is Mobilized Cohesion?

Definition: Mobilized Cohesion is the amount of cohesion that is resisting the shear stress in soil mechanics.

Purpose: It helps geotechnical engineers determine the actual cohesion value that is being utilized to resist shear forces in soil.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ C_m = \frac{c}{F_c} \]

Where:

\( C_m \) — Mobilized Cohesion (Pa)
\( c \) — Cohesion of Soil (Pa)
\( F_c \) — Factor of Safety with respect to Cohesion (±5%)

Explanation: The cohesion of soil is divided by the factor of safety to determine the mobilized cohesion value.

3. Importance of Mobilized Cohesion Calculation

Details: Proper calculation of mobilized cohesion ensures safe slope stability analysis and foundation design, accounting for safety margins.

4. Using the Calculator

Tips: Enter the cohesion of soil in Pascals and the factor of safety (with ±5% tolerance). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical factor of safety for cohesion?
A: Common values range from 1.5 to 3.0 depending on project requirements and soil conditions.

Q2: Why is there a ±5% tolerance on the factor of safety?
A: This accounts for uncertainties in soil testing and variations in field conditions.

Q3: How do I determine the cohesion value of soil?
A: Cohesion is typically determined through laboratory tests like the unconfined compression test or triaxial test.

Q4: What units should I use for cohesion?
A: The calculator uses Pascals (Pa), but kN/m² is also common (1 kN/m² = 1000 Pa).

Q5: When would mobilized cohesion be equal to soil cohesion?
A: Only when the factor of safety is exactly 1.0, which is generally unsafe for practical applications.