Abstract:
The project focuses on understanding the phenomenon of soil liquefaction; the factors triggering
it, soil behavior during liquefaction and the methods to mitigate liquefaction. Liquefaction occurs
when cohesion less saturated soil losses is strength due to excess pore water pressure, and begins
to flow when subjected to external loading. The loading is usually cyclic or seismic loading like
earthquakes. This phenomenon has inflicted loss of life and property in different countries like
Japan and Taiwan, and therefore requires attention of future civil engineers
The report outlines the methods to evaluate liquefaction, namely simplified semi-empirical
procedure and shear wave velocity method. Semi-empirical procedure, evaluates a factor of safety
against liquefaction by dividing cyclic stress ratio with cyclic resistance ratio. The cyclic stress ratio
is the ratio of maximum and minimum stresses induced by an earthquake. The cyclic resistance
ratio is the value of cyclic stress that would lead to liquefaction. Shear wave velocity method is a
non penetrative technique that uses value of shear wave velocities to evaluate resistance ratio
and eventually the factor if safety.
The report also outlines methods to mitigate liquefaction. Different ground improvement
techniques have been explained. Lastly, we have designed and assembled a liquefaction tank to
physically demonstrate liquefaction. The components and working of the tank are explained in the
report below.
