Designing a pavement section in Nashville means accounting for two very different soil worlds. Over in West End and Belle Meade, you hit those deep, stiff cherty clays that look like they'd support anything—until they don't, especially after a wet spring. But cross the river into East Nashville or head toward Donelson, and the picture flips: alluvial silts and sandy loams along the Cumberland floodplain that can pump and rut under traffic if the CBR is misjudged. A test pit investigation into these contrasting profiles reveals why a single assumed bearing value is a gamble. Our laboratory CBR test quantifies that variability precisely, giving you soaked and unsoaked strength numbers you can plug straight into the AASHTO 93 design equation for each distinct subgrade unit on the project.
The soaked CBR value is the one that governs in Middle Tennessee—our subgrades rarely stay dry once construction starts.
