Submerged Unit Weight given Weighted and Mobilised Friction Angle Calculator

Submerged Unit Weight Formula:

\[ \gamma' = \frac{\gamma_{sat} \times \phi_w}{\phi_m} \]

Saturated Unit Weight (γ_sat):

N/m³

Weighted Friction Angle (φ_w):

rad

Angle of Mobilized Friction (φ_m):

rad

Submerged Unit Weight (γ'): N/m³

1. What is Submerged Unit Weight?

Definition: Submerged Unit Weight is the effective weight of soil per unit volume when submerged in water.

Purpose: It's crucial in geotechnical engineering for analyzing soil stability under water-saturated conditions.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \gamma' = \frac{\gamma_{sat} \times \phi_w}{\phi_m} \]

Where:

\( \gamma' \) — Submerged unit weight (N/m³)
\( \gamma_{sat} \) — Saturated unit weight (N/m³)
\( \phi_w \) — Weighted friction angle (radians)
\( \phi_m \) — Angle of mobilized friction (radians)

Explanation: The formula calculates the effective weight of submerged soil considering both friction properties and saturation conditions.

3. Importance of Submerged Unit Weight Calculation

Details: Accurate calculation is essential for designing foundations, retaining walls, and slope stability analysis in water-saturated soils.

4. Using the Calculator

Tips: Enter the saturated unit weight in N/m³, weighted friction angle in radians (±5%), and mobilized friction angle in radians (±5%). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between saturated and submerged unit weight?
A: Saturated unit weight includes water in pores, while submerged unit weight accounts for buoyancy effects when soil is underwater.

Q2: Why are angles in radians?
A: Radians are the standard angular measurement in most engineering calculations, especially in trigonometric functions.

Q3: What does ±5% mean for the angles?
A: It indicates the typical measurement uncertainty range for these parameters in field conditions.

Q4: How do I convert degrees to radians?
A: Multiply degrees by π/180 (approximately 0.0174533).

Q5: When would this calculation be used?
A: Primarily in underwater construction, dam design, and any geotechnical work involving water-saturated soils.