Neutral Stress per unit area for Dams on Soft Foundations Calculator

Neutral Stress Formula:

\[ \sigma_{Neutral\ stress} = D \times W \times (1 + \frac{h}{L_n}) \]

Depth of Dam (D):

Specific Weight of Water (W):

N/m³

Height of Dam (h):

Minimum Safe Length (Lₙ):

Tolerance:

Neutral Stress (σ): Pa

1. What is Neutral Stress in Dams?

Definition: Neutral stress in a soil mass is a force per effective area - stress taken up by the pore water and stress taken up by solid particles.

Purpose: This calculation is crucial for designing dams on soft foundations to ensure stability and prevent failure.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \sigma_{Neutral\ stress} = D \times W \times (1 + \frac{h}{L_n}) \]

Where:

\( \sigma_{Neutral\ stress} \) — Neutral stress (Pascals)
\( D \) — Depth of Dam (meters)
\( W \) — Specific weight of water (N/m³, default 9810)
\( h \) — Height of Dam (meters)
\( L_n \) — Minimum safe length of travel path (meters)

Explanation: The formula calculates the stress distribution considering the dam's geometry and water pressure.

3. Importance of Neutral Stress Calculation

Details: Proper stress calculation ensures dam stability, prevents foundation failure, and helps in designing appropriate reinforcement.

4. Using the Calculator

Tips: Enter all dimensions in meters. The tolerance field (default ±5%) allows for safety margin calculations.

5. Frequently Asked Questions (FAQ)

Q1: What is typical specific weight of water?
A: Fresh water at 4°C has a specific weight of 9810 N/m³ (9.81 kN/m³).

Q2: How to determine minimum safe length?
A: This depends on foundation material properties and is typically determined through geotechnical analysis.

Q3: Why include a tolerance percentage?
A: The tolerance accounts for material variations, measurement uncertainties, and safety factors.

Q4: What units are used in the calculation?
A: All inputs should be in meters (m) and Newtons per cubic meter (N/m³). Results are in Pascals (Pa).

Q5: How does dam height affect neutral stress?
A: Higher dams create greater water pressure, increasing neutral stress proportionally.