Implementation of Finite Element Method for Prediction of Soil Liquefaction Around Undergroud Structure


Liquefaction is the rapid loss of shear strength in cohesionless soils subjected to dynamic loading, that it is a state of saturated cohesionless soil when its entire shear strength is reduced to zero due to pore water pressure caused by vibration. Liquefaction depends on the nature, magnitude and type of dynamic loading. An entire stratum may be liquefied at the same time under shock loading, or liquefaction may start at the top and proceed downward with steady-state vibrations. In this paper, finite element method is used in an attempted to study liquefaction of soil based on the case solved previously by transient infinite element for 2D soil - structure interaction analysis considering infinite boundaries but without generation of pore water pressure. The properties of fully saturated sandy soil and concrete are fed to geotechnical finite element software called QUAKE/W program. The results showed that liquefaction occurs faster at shallow depths due to low overburden pressure. Also, liquefaction zones and deformation occur faster with the increase of dynamic loading amplitude. The analysis marked that increasing the amplitude pressure accelerates the occurrence of initial liquefaction and increases the pore water pressure.