The design of stone columns in Houston must address the Beaumont Formation clays and loose Pleistocene sands that underlie much of Harris County. IBC Section 1803 requires site-specific geotechnical data, and ASTM D1586 standard penetration tests consistently show N-values below 8 in the upper 20 feet across the metro area. These soft compressible soils demand rigorous Improvement before structural loads can be transferred safely. Our laboratory processes undisturbed Shelby tube samples to measure undrained shear strength, which feeds directly into the unit cell model for the stone column design. With a groundwater table often just 6 feet below grade, the installation method matters as much as the spacing calculation, and we verify both during field trials before production begins.
A properly instrumented modulus test on a stone column tells you more about the composite ground stiffness than a dozen SPT borings alone.
