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.
