ASTM International

Standard Practice for Determining the Normalized Penetration Resistance of Sands for Evaluation of Liquefaction Potential
 N D6066

Annotation

This practice outlines a procedure to obtain a record of normalized resistance of sands to the penetration of a standard sampler driven by a standard energy for estimating soil liquefaction potential during earthquakes. The normalized penetration resistance determined in this practice may be useful for determination of other engineering properties of sands.

This practice uses Test Method D1586 with additions and modifications to minimize disturbance of saturated loose cohesionless sands during drilling. This practice combines results of Test Method D1586 and interprets the data for normalization purposes.

Due to inherent variability of the SPT, guidance is given on test configuration and energy adjustments. Penetration resistance is adjusted for energy delivered in the penetration test. Energy adjustments can be estimated or measured and reported.

Standard practice for normalizing penetration resistance values is given. Penetration resistance data are normalized to a standard overburden stress level.

The normalized penetration resistance data may be used to estimate liquefaction resistance of saturated sands from earthquake shaking. Evaluation of liquefaction resistance may be applied to natural ground conditions or foundations for either planned or existing structures.

Using this practice representative disturbed samples of the soil can be collected for identification purposes.

This practice is limited to use in cohesionless soils (see Test Method D2487 and classifications of SM, SW, SP, SP-SM, and SW-SM Practice D2488). In most cases, testing is performed in saturated deposits below the water table. In some cases, dry sands may be tested. This practice is not applicable to lithified materials or fine grained soils. Gravel can interfere with the test and result in elevated penetration resistance values. Normalization of penetration resistance values for gravelly soils is beyond the scope of this practice.