Understanding ASTM D2166: The Standard for Unconfined Compression Strength of Cohesive Soil (PDF Overview)
For geotechnical engineers and laboratory technicians, determining the shear strength of cohesive soils is a fundamental task. The go-to standard for this—particularly for soils that do not require complex confinement—is ASTM D2166 . Whether you are reviewing a report or setting up a lab test, having a clear grasp of this standard is critical. astm d2166 pdf
ASTM D2166, officially titled "Standard Test Method for Unconfined Compressive Strength of Cohesive Soil," measures the unconfined compressive strength (qu) of saturated, cohesive soils. This value is then used to estimate the soil's undrained shear strength (Su), typically calculated as Su = qu/2. ASTM D2166, officially titled "Standard Test Method for
ASTM D2166 is a cornerstone of geotechnical lab testing. While the unconfined compression test has limitations, it remains an indispensable tool for preliminary strength assessments. For critical projects, pair it with triaxial or direct shear testing. While the unconfined compression test has limitations, it
Always check the active version. As of this post, the latest designation is ASTM D2166 / D2166M-16 (2023) . The "M" indicates metric units (SI) are now fully integrated.