Area Ratio for Soil Sampler Calculator

Area Ratio Formula:

\[ Ar = \frac{(D2^2 - D1^2)}{D1^2} \]

Area Ratio:

Tolerance Range (±5%):

1. What is Area Ratio for Soil Sampler?

Definition: Area Ratio for Soil Sampler is defined as ratio of the volume of soil displaced by the sampler tube in proportion to the volume of the sample.

Purpose: It helps geotechnical engineers evaluate the disturbance caused by sampling and ensure sample quality.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Ar = \frac{(D2^2 - D1^2)}{D1^2} \]

Where:

\( Ar \) — Area Ratio (dimensionless)
\( D2 \) — Outer Diameter Of Cutting Edge (m)
\( D1 \) — Inner Diameter Of Cutting Edge (m)

Explanation: The formula calculates the ratio between the displaced soil area and the sample area.

3. Importance of Area Ratio Calculation

Details: Lower area ratios indicate less disturbance to the soil sample. Generally, ratios below 10-15% are preferred for undisturbed sampling.

4. Using the Calculator

Tips: Enter the outer and inner diameters in meters, and the tolerance percentage (default ±5%). All diameter values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a good area ratio value?
A: For undisturbed sampling, aim for values below 10-15%. Higher values indicate more soil disturbance.

Q2: How does tolerance affect the results?
A: The tolerance percentage shows the acceptable variation range (±5% by default) around the calculated area ratio.

Q3: What units should I use for diameters?
A: The calculator uses meters, but any consistent unit can be used since the ratio is dimensionless.

Q4: Why is inner diameter squared in the formula?
A: The formula compares areas (which are proportional to diameter squared), not linear dimensions.

Q5: Can I use this for other sampling tools?
A: Yes, the formula applies to any cylindrical sampling tool where you know the inner and outer diameters.