Liquefaction
and related phenomena have been responsible for tremendous amounts of
damage in historical earthquake around the world. Especially, its
devastating effects sprang to the attention of geotechnical engineers
in a three-month period in 1964 when the Niigata earthquake in Japan
followed the Good Friday earthquake in Alaska. Evaluation of
liquefaction resistance of soils is an important step in many
geotechnical investigations in earthquake-liable region. The most
common procedure around the world for evaluating liquefaction
resistance is “simplified procedure” developed originally by Seed and
Idriss (1971) using blow counts from the Standard Penetration Test
correlated with a parameter called the cyclic stress ratio, which
represents the cyclic loading on the soil. Since 1971, this procedure
has been modified and updated. Parallel procedures based on Cone
Penetration Test, Shear wave velocity measurements, and Becker
Penetration Test was introduced and has been revised and updated.
The simplified procedures are based on empirical considerations and
have provided useful methods for identifying liquefaction potentials of
soils. However, there has been a growing recognition that elementary
consideration of the mechanism of liquefaction can provide improved
characterization for liquefaction. The energy approach is considered to
be one such mechanistic procedure.
