The Coefficient of Permeability Calculator determines the permeability of a soil sample, which measures its ability to allow water to flow through its pores. This is a critical factor in geotechnical engineering, environmental studies, and groundwater flow analysis. The calculator simplifies the process by requiring only a few inputs to compute permeability, which is essential for designing drainage systems, assessing soil stability, and evaluating groundwater contamination risks.
This calculator belongs to the geotechnical and environmental engineering tools category and is widely used by civil engineers, hydrologists, and environmental scientists.
Formula of Coefficient Of Permeability Calculator
The formula for calculating the coefficient of permeability (k) is:
k = (Q * L) / (A * t * h)
Where:
- k: Coefficient of permeability (cm/sec or m/sec)
- Q: Volume of water discharged (cm³ or m³)
- L: Length of the soil sample (cm or m)
- A: Cross-sectional area of the soil sample (cm² or m²)
- t: Time taken for the water to flow (sec)
- h: Hydraulic head difference (cm or m)
Steps to Calculate
- Measure the length of the soil sample (L) and its cross-sectional area (A).
- Record the volume of water discharged (Q) during a time period (t).
- Determine the hydraulic head difference (h).
- Substitute these values into the formula to calculate the coefficient of permeability.
Interpretation
- High permeability (large k value): Indicates that water flows easily through the soil, common in sandy soils.
- Low permeability (small k value): Indicates restricted water flow, typical of clayey soils.
Table for Common Permeability Ranges
The table below provides typical permeability values for different soil types:
| Soil Type | Coefficient of Permeability (k) (m/sec) |
|---|---|
| Gravel | > 1 × 10⁻³ |
| Sand | 1 × 10⁻⁴ to 1 × 10⁻³ |
| Silty Sand | 1 × 10⁻⁶ to 1 × 10⁻⁴ |
| Clay | < 1 × 10⁻⁷ |
This table offers a quick reference for understanding soil permeability without performing calculations.
Example of Coefficient Of Permeability Calculator
Let’s calculate the coefficient of permeability for a soil sample.
Given Data:
- Volume of water discharged (Q): 200 cm³
- Length of soil sample (L): 10 cm
- Cross-sectional area (A): 50 cm²
- Time (t): 300 seconds
- Hydraulic head difference (h): 5 cm
Step 1: Use the formula
k = (Q * L) / (A * t * h)
Step 2: Substitute the given values
k = (200 * 10) / (50 * 300 * 5)
Step 3: Perform the calculation
k = 2000 / 7500
k = 0.267 cm/sec
Interpretation: The coefficient of permeability is 0.267 cm/sec, which indicates high permeability suitable for applications like drainage systems.
Most Common FAQs
The coefficient of permeability (k) quantifies the ease with which water flows through soil pores. It is a critical property for understanding soil behavior in various applications.
Permeability determines how soil interacts with water, affecting the design of foundations, retaining walls, and drainage systems. It also plays a vital role in groundwater flow studies.
No, permeability cannot be negative because it represents the physical flow capacity of a medium, which is always a positive value.