Shrinkage Ratio of Soil Calculator

Shrinkage Ratio Formula:

\[ SR = \frac{\gamma_{dry}}{\gamma_{water}} \]

Shrinkage Ratio:

1. What is Shrinkage Ratio of Soil?

Definition: Shrinkage ratio is the ratio of a given volume change expressed as a percentage of dry volume to the corresponding change in water content.

Purpose: It helps geotechnical engineers understand how much soil will shrink as it dries, which is important for construction and foundation design.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ SR = \frac{\gamma_{dry}}{\gamma_{water}} \times 100 \]

Where:

\( SR \) — Shrinkage Ratio (%)
\( \gamma_{dry} \) — Dry Unit Weight of soil (N/m³)
\( \gamma_{water} \) — Unit Weight of Water (N/m³, typically 9810 N/m³)

Explanation: The dry unit weight is divided by the unit weight of water and multiplied by 100 to get the shrinkage ratio as a percentage.

3. Importance of Shrinkage Ratio Calculation

Details: Understanding shrinkage ratio helps predict soil behavior during drying, preventing structural damage from soil movement in construction projects.

4. Using the Calculator

Tips: Enter the dry unit weight of soil in N/m³ and unit weight of water (default 9810 N/m³). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical shrinkage ratio value?
A: Most soils have shrinkage ratios between 0.5% to 5%, but highly expansive clays can have much higher values.

Q2: Why is the result multiplied by 100?
A: The multiplication converts the decimal ratio to a percentage for easier interpretation.

Q3: What's the standard unit weight of water?
A: The unit weight of water is typically 9810 N/m³ (or 9.81 kN/m³) at standard conditions.

Q4: How do I measure dry unit weight of soil?
A: Dry unit weight is determined by laboratory tests where a soil sample is dried and weighed.

Q5: Does temperature affect the shrinkage ratio?
A: Temperature primarily affects water content but the ratio itself is a fundamental property of the soil.