Number of Beds given discharge for Dams on Soft Foundations Calculator

Number of Beds Formula:

\[ B = \frac{k \times H_{water} \times N}{Q_t} \]

Coefficient of Permeability of Soil:

m/s

Head of Water:

Equipotential Lines:

Discharge from Dam:

m³/s

Number of Beds:

1. What is Number of Beds for Dams on Soft Foundations?

Definition: This calculator determines the number of beds needed between equipotential lines based on soil permeability, water head, and dam discharge.

Purpose: It helps civil engineers design proper drainage systems for dams built on soft foundations to prevent seepage and ensure stability.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ B = \frac{k \times H_{water} \times N}{Q_t} \]

Where:

\( B \) — Number of beds
\( k \) — Coefficient of permeability of soil (m/s)
\( H_{water} \) — Head of water (m)
\( N \) — Number of equipotential lines (±5%)
\( Q_t \) — Discharge from dam (m³/s)

Explanation: The formula calculates how many beds are needed between equipotential lines to properly distribute the water flow through the dam foundation.

3. Importance of Bed Calculation

Details: Proper bed calculation ensures effective seepage control, prevents piping failure, and maintains dam structural integrity on soft foundations.

4. Using the Calculator

Tips: Enter soil permeability (default 0.1 m/s), water head (default 2.3 m), equipotential lines (default 4 ±5%), and discharge (default 0.46 m³/s). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of equipotential lines ±5%?
A: The ±5% accounts for potential measurement variations in determining equipotential lines in flow nets.

Q2: How is soil permeability coefficient determined?
A: It's typically measured through laboratory tests like constant head or falling head permeability tests.

Q3: What affects the head of water in this calculation?
A: Reservoir water level, dam height, and foundation depth all influence the effective head of water.

Q4: When would I need more beds?
A: More beds are needed with higher permeability soils, greater water heads, or when trying to reduce discharge rates.

Q5: How does this relate to dam safety?
A: Proper bed calculation prevents excessive seepage that could lead to foundation erosion or dam failure.