Soil Liquefaction

This project provides knowledge on liquefaction of soils. Liquefaction can be defined as a process that creates a non-liquid phase to behave as per fluid dynamics. Soil liquefaction is when soil merely behaves like a liquid mass with hardly any shear strength rather than a solid mass. Liquefaction causes soil failures and, therefore, severe damages to structures supported on such grounds leading to significant economic losses.
In this project liquefaction has been divided into two broad categories, these are liquefaction due to flow and liquefaction due to chemical processes in particular dispersive soils since structural failures attributed to dispersive soils have occurred in many countries worldwide as dispersive clay soils deflocculate and are rapidly eroded and carried away by water flow.
Presented also are the various criteria used for evaluating soil susceptible to liquefaction, ground failures resulting from soil liquefaction, factors affecting liquefaction and the in-situ testing procedures used to assess liquefaction of soils.
A case study of the Niigata earthquake in Japan, 1964 was chosen as a sample to show the tremendous damaging effects of liquefaction due to flow as this was one of the cases that brought the phenomenon of liquefaction to the attention of geotechnical engineers.
Another case study of Wister Dam, Oklahoma, 1949 was chosen as a sample as its unique erosional patterns, led to the identification of dispersive clay and its negative behavioral properties. It also led the geotechnical engineering community to the conclusion that homogeneous dams are unsafe without internal drains or filters to control concentrated leaks.
Finally, the various methods used to mitigate the dangers of liquefaction at a site are also discussed.