ASTM D1586 Fact Sheet

The ASTM D1586 standard details the Standard Penetration Test (SPT) and Split-Barrel Sampling method, essential for evaluating soil properties in construction. This test measures soil penetration resistance and collects samples using a split-spoon sampler, driven by a 140-lb hammer dropped 30 inches, deployed via a drilling rig. The process involves driving the sampler through three 6-inch increments, recording blow counts to calculate the N-value (sum of second and third increments), and retrieving the sample.

The N-value helps assess soil density and strength, supporting classification, though additional tests are required. It’s widely used for site investigations and foundation design to determine suitability. The method offers field simplicity and immediate data, but it can disturb soil, varies with equipment and operator, and provides an indirect measure of strength. Safety considerations include handling heavy machinery and ensuring borehole stability.