Mechanisticempirical

Mechanistic-empirical design is an approach in engineering that blends physics-based (mechanistic) modeling of material behavior under loads with empirical correlations drawn from observed performance data. The goal is to predict performance and service life more accurately than purely empirical methods by incorporating loading, geometry, material properties, and climate into a coherent design framework while grounding predictions in field experience.

In pavement engineering, the mechanistic-empirical method gained prominence in the late 20th century and was formalized in the United States through the Mechanistic-Empirical Pavement Design Guide (MEPDG) and its successors. The approach treats pavements as layered systems, uses material properties such as modulus and strength, and translates computed stresses and strains under traffic and environmental conditions into probabilistic distress predictions via empirical performance models.

The process typically involves developing mechanistic models to estimate stresses, strains, and deformations in pavement components, selecting appropriate traffic loads and climate inputs, and then applying empirical relationships that relate those responses to distresses such as rutting, fatigue cracking, and low-temperature cracking. Calibration with local performance data improves reliability and enables design predictions over a chosen service life.

Applications extend beyond pavements to other civil engineering domains, including structural and geotechnical design, where mechanistic calculations are linked to empirical performance observations. Advantages include improved physical realism and the ability to adapt designs to local conditions, while limitations involve the need for accurate material characterization, reliable performance data, and substantial calibration for new materials or climates.