1
Department of Civil Engineering, Yazd University
2
Civil Engineering Departement,Yazd University
10.22075/jtie.2025.38579.1730
Abstract
The composite foundation reaction modulus (K∞) is a vital parameter in concrete pavement design, characterizing pavement-subgrade interaction behavior and directly influencing stress distribution and deformation in concrete slabs. Traditional determination methods relying on code-based design charts (Code 731 and AASHTO 1993) face data extraction challenges that limit modeling accuracy. This study develops an innovative numerical model for K∞ using data extracted from these charts, assuming a semi-infinite subgrade. Primary objectives include precise chart data extraction, fitting regression models (linear, polynomial, exponential, power, logarithmic), and selecting the optimal mathematical relationship using rigorous statistical criteria. Model performance was evaluated via coefficient of determination (R²), adjusted R², standard error of estimate (SEE), and residual analysis. Results indicate the power model achieves superior statistical performance with R² = 97.41% and low SEE = 0.1308, alongside optimal residual behavior, explaining K∞’s nonlinear dependence on subbase thickness, subbase elastic modulus, and subgrade soil modulus. Analysis revealed K∞ is critically influenced by: synergy between subbase thickness and elastic modulus; subbase’s protective effect on subgrade, and; a subbase thickness threshold condition. These mechanical interactions govern pavement-subgrade system stiffness. The research provides an efficient methodology to convert design charts into analytical equations, enhancing accuracy, reducing human error, and enabling integration into sensitivity analyses and concrete slab thickness optimization under variable subbases.
jokar, M. , Khabiri, M. M. , Sarfaraz, S. and temory, M. (2025). Mathematical Modeling for Determining Concrete Pavement’s Composite Foundation Reaction Modulus (K∞) Using Regression Optimization. Journal of Transportation Infrastructure Engineering, (), -. doi: 10.22075/jtie.2025.38579.1730
MLA
jokar, M. , , Khabiri, M. M. , , Sarfaraz, S. , and temory, M. . "Mathematical Modeling for Determining Concrete Pavement’s Composite Foundation Reaction Modulus (K∞) Using Regression Optimization", Journal of Transportation Infrastructure Engineering, , , 2025, -. doi: 10.22075/jtie.2025.38579.1730
HARVARD
jokar, M., Khabiri, M. M., Sarfaraz, S., temory, M. (2025). 'Mathematical Modeling for Determining Concrete Pavement’s Composite Foundation Reaction Modulus (K∞) Using Regression Optimization', Journal of Transportation Infrastructure Engineering, (), pp. -. doi: 10.22075/jtie.2025.38579.1730
CHICAGO
M. jokar , M. M. Khabiri , S. Sarfaraz and M. temory, "Mathematical Modeling for Determining Concrete Pavement’s Composite Foundation Reaction Modulus (K∞) Using Regression Optimization," Journal of Transportation Infrastructure Engineering, (2025): -, doi: 10.22075/jtie.2025.38579.1730
VANCOUVER
jokar, M., Khabiri, M. M., Sarfaraz, S., temory, M. Mathematical Modeling for Determining Concrete Pavement’s Composite Foundation Reaction Modulus (K∞) Using Regression Optimization. Journal of Transportation Infrastructure Engineering, 2025; (): -. doi: 10.22075/jtie.2025.38579.1730
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