What Is the Pavement Subgrade Modulus of Reaction (k-value) Calculator?
Convert California Bearing Ratio (CBR) to Resilient Modulus (MR) and Westergaard modulus of subgrade reaction (k-value) for rigid pavement design.
The Pavement Subgrade Modulus of Reaction (k-value) Calculator is an analytical tool in the construction domain designed to evaluate California Bearing Ratio (CBR), Subgrade Soil Type using verified mathematical equations. It provides reproducible, deterministic calculations for academic, professional, and practical applications.
How Does the Pavement Subgrade Modulus of Reaction (k-value) Calculator Work?
This calculator computes results by taking input values for California Bearing Ratio (CBR), Subgrade Soil Type and applying the governing equation: MR is resilient modulus, k is modulus of subgrade reaction in pounds per cubic inch, and k_SI is modulus in megapascals per meter.. Values are checked for dimensional consistency and processed through standard arithmetic routines.
Pavement Subgrade Modulus of Reaction (k-value) Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
MR is resilient modulus, k is modulus of subgrade reaction in pounds per cubic inch, and k_SI is modulus in megapascals per meter.
How to Use the Pavement Subgrade Modulus of Reaction (k-value) Calculator
- Enter your value for California Bearing Ratio (CBR) in %.
- Enter your value for Subgrade Soil Type.
- Verify your input parameters to ensure they match your design or problem specifications.
- Review the calculated results, intermediate mathematical steps, and graphical visualization below.
Step-by-Step Example Calculation
Highway Subgrade Silt Soil
Input Values:
Understanding Your Result
The calculated output gives the primary solution for Pavement Subgrade Modulus of Reaction (k-value) under the specified conditions. Use this value to compare against standard design tolerances, benchmarks, or reference ranges in construction.
Factors That Affect the Result
- Input precision and measurement accuracy of California Bearing Ratio (CBR), Subgrade Soil Type.
- Operating conditions, environmental parameters, and specific construction tolerances.
- Boundary constraints and deviations from nominal theoretical model assumptions.
When Should You Use This Calculator?
- When performing technical analysis or dimensioning related to Pavement Subgrade Modulus of Reaction (k-value).
- To cross-verify manual calculations or theoretical models in construction.
- For preliminary estimates before conducting detailed field measurements or laboratory testing.
Assumptions & Limitations
- AASHTO correlation: MR (psi) = 1500 · CBR for fine-grained soils (CBR ≤ 10).
- Westergaard k-value correlation: k (pci) ≈ MR (psi) / 19.4 per PCA / AASHTO Guide.
- Conversion: 1 pci = 0.27144 MPa/m.
Frequently Asked Questions
What is the modulus of subgrade reaction (k)?+
How does Resilient Modulus (MR) correlate to k?+
Calculation Accuracy & Reference Note
This calculator implements verified mathematical formulas for Pavement Subgrade Modulus of Reaction (k-value) Calculator. Always verify critical results against official domain standards and manufacturer documentation.