Submerged Unit Weight given Critical Depth Calculator

Submerged Unit Weight Formula:

\[ \gamma' = \frac{C_s \cdot \sec^2(i)}{h_c \cdot (\tan(i) - \tan(\phi))} \]

Cohesion of Soil:

kPa

Angle of Inclination:

rad

Critical Depth:

Angle of Internal Friction:

rad

Tolerance:

Submerged Unit Weight: kN/m³

1. What is Submerged Unit Weight?

Definition: Submerged Unit Weight is the unit weight of soil observed underwater in a saturated condition.

Purpose: It's crucial for analyzing soil stability in underwater conditions, such as for foundations of underwater structures or slope stability analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \gamma' = \frac{C_s \cdot \sec^2(i)}{h_c \cdot (\tan(i) - \tan(\phi))} \]

Where:

\( \gamma' \) — Submerged unit weight (kN/m³)
\( C_s \) — Cohesion of soil (kPa)
\( i \) — Angle of inclination to horizontal (rad)
\( h_c \) — Critical depth (m)
\( \phi \) — Angle of internal friction (rad)

Explanation: The formula calculates the submerged unit weight based on soil cohesion, inclination angle, critical depth, and internal friction angle.

3. Importance of Submerged Unit Weight Calculation

Details: Accurate calculation is essential for designing stable underwater structures, analyzing slope stability in submerged conditions, and preventing soil liquefaction.

4. Using the Calculator

Tips: Enter all required parameters in their respective units. The tolerance field (default ±5%) allows you to specify an acceptable range for the result.

5. Frequently Asked Questions (FAQ)

Q1: What is critical depth in this context?
A: Critical depth is the depth of flow where energy is at a minimum for a particular discharge in soil mechanics applications.

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

Q3: Why include a tolerance percentage?
A: Soil properties can vary, so the tolerance provides an acceptable range to account for natural variability in soil conditions.

Q4: Can I use degrees instead of radians?
A: The calculator requires radians. Convert degrees to radians by multiplying by π/180.

Q5: What's a typical range for submerged unit weight?
A: Most soils range between 8-12 kN/m³ when submerged, but this can vary significantly based on soil type and conditions.