This paper reviews the characteristics of soil liquefaction-induced damage observed from the Northridge

USA earthquake

1994

the Hanshin

Japan earthquake

1995

the Kocaeli

Turkey earthquake

1999

the Chi-Chi

Taiwan earthquake

1999

in China

the Wenchuan

China earthquake

2008

the Maule

Chile Earthquake

2010

the Darfield and Christchurch

New Zealand earthquake

2010 to 2011

and the great East Japan earthquake

2011. There are several characteristics in the occurrence of liquefaction and consequence damage which are different from a number of cases experienced in these earthquakes. These are summed up as follows: (1) The unprecedented long duration of the shaking and extensive makes the occurrence of liquefaction in the newly reclaimed land

fill area is 300~400 km distant from the epicentral area attributed to the rarely encountered huge moment magnitude Mw9.0 earthquake. (2) A number of site liquefactions and lateral spreadings are observed in seismic intensity scales of Ⅴ and Ⅵ

an area of low intensity is attributed to the encountered magnitude scale Ms8.0 and Mw8.8 earthquakes. (3) Severe liquefactions in sites are observed having young alluvial

lacustrine deposits along rivers and sea bay areas

and in reclaimed land

fill area contains fine-grained soils

gravel sands in less than fifty years. (4) Severe liquefaction in natural gravel sand deposits occurs. (5) Soil liquefies in depth of 20 m. (6) Liquefaction and re-liquefaction of the sites over a large region do not result in densification of the loose deposit

future earthquakes of sufficient magnitude can again induce liquefaction. (7) Severe liquefaction occurs in low to moderate plasticity soils containing more than 50% fines content (grain size is

smaller than 0.075 mm) or more than 25% of clay content (grain size is

smaller than 0.005mm)

however

field evidence of liquefaction may not be observed in transition behavior fine-grained soils between sand-like and clay-like behaviors. (8) Ground cracking without venting of sand boils is more likely as the depth and thickness of the liquefied layer increases and decreases

respectively; vented material

provided field evidence of liquefaction

may be absent due to the large depth to

and small thickness of

the liquefied layers. There are a number of spectacular case histories of liquefaction of sediments deposited in late Pleistocene time Q3. The clay content is not a reliable index for evaluating between clay-like and sand-like behaviors in a fine-grained soil. Fine-grained soils with the low plasticity index PI and high water content wc are susceptible to liquefaction; the use of the PI and water content to liquid limit ratio wc/LL is a good criterion of liquefaction possibility; for soils. Based on work in progress of the case histories of liquefaction and the results of laboratory tests for fine-grained soils from Boulanger

Idriss

Bray and Sancio

Seed and Cetin et al

a new liquefaction possibility criterion for soils is proposed as follows: soils with PI<12 and wc/LL>0.85 are susceptible to liquefaction; soils with 1220 or wc/LL<0.80 is not susceptible to liquefaction.