Which measure determines the quality of strength of soil underlying pavement?

The California Bearing Ratio (CBR) is a critical measure used to determine the strength and load-bearing capacity of subgrade soil, specifically for pavement design. This test assesses how well the soil can support the weight of the pavement and any traffic loads it will carry. The CBR value is calculated by comparing the strength of the soil to that of a standard crushed stone material, which allows engineers to evaluate the soil's ability to bear loads effectively.

Using the CBR test results, engineers can make informed decisions about the thickness of the pavement and the materials needed. A higher CBR value indicates a stronger subgrade capable of supporting heavier loads, while a lower value may suggest the need for additional paving thickness or alternative materials to ensure the pavement's integrity and longevity under traffic conditions.

While moisture content, soil compaction, and shear strength are relevant factors in soil analysis and construction, they serve different purposes and do not directly provide the specific load-bearing capability assessment that the CBR does in the context of pavement design.