Unit Weight of Water Given Bulk Specific Gravity of Soil Calculator

Unit Weight of Water Formula:

\[ \gamma_{water} = \frac{\gamma_{bulk}}{G_m} \]

Unit Weight of Water (kN/m³):

1. What is Unit Weight of Water Given Bulk Specific Gravity?

Definition: This calculator determines the unit weight of water based on the bulk unit weight of soil and its bulk specific gravity.

Purpose: It helps geotechnical engineers and soil scientists understand the relationship between soil properties and water content.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \gamma_{water} = \frac{\gamma_{bulk}}{G_m} \]

Where:

\( \gamma_{water} \) — Unit weight of water (kN/m³)
\( \gamma_{bulk} \) — Bulk unit weight of soil (kN/m³)
\( G_m \) — Bulk specific gravity of soil (dimensionless)

Explanation: The bulk unit weight is divided by the bulk specific gravity to obtain the unit weight of water.

3. Importance of This Calculation

Details: Understanding this relationship is crucial for soil mechanics calculations, including porosity, void ratio, and degree of saturation.

4. Using the Calculator

Tips: Enter the bulk unit weight in kN/m³ and bulk specific gravity (typically 2.6-2.8 for most soils). The bulk specific gravity has a ±5% tolerance.

5. Frequently Asked Questions (FAQ)

Q1: What is bulk specific gravity?
A: It's the ratio of the bulk unit weight of soil to the unit weight of water.

Q2: Why is there a ±5% tolerance?
A: Bulk specific gravity can vary due to soil composition, moisture content, and testing methods.

Q3: What's a typical bulk unit weight for soils?
A: Most soils range from 16-22 kN/m³, depending on density and water content.

Q4: How is this different from specific gravity of solids?
A: Bulk specific gravity includes voids, while specific gravity of solids refers only to the mineral particles.

Q5: What is the standard unit weight of water?
A: Pure water at 4°C has a unit weight of 9.81 kN/m³, which is often used as a reference value.