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Liquefaction Potential Index (LPI) calculation procedure <br />Calculation of the Uquefaction Potential Index (LPI) is used to interpret the liquefaction assessment calculations in terms of <br />severity over depth. The calculation procedure is based on the methology developed by Iwasaki (1982) and is adopted by AFPS. <br />To estimate the severity of liquefaction extent at a given site, LPI is calculated based on the following equation: <br />20 <br />LPI = [(10 -0,5z)><Fi><dz <br />where: <br />FL =1- F.S. when F.S. less than 1 <br />FL = O when F.S. greater than 1 <br />z depth of measurment in meters <br />Values of LPI range between zero (0) when no test point is characterized as liquefiable and 100 when all points are characterized <br />as susceptible to liquefaction. Iwasaki proposed four (4) discrete categories based on the numeric value of LPI: <br />• LPI = O Liquefaction risk is very low <br />• 0 < LPI <= 5 : Liquefaction risk is low <br />• 5 < LPI <= 15 : Liquefaction risk is high <br />• LPI > 15 :Liquefaction risk is very high <br />00 1.0 2.0 0 <br />0 0 <br />P <br />5 5 <br />E <br />10' <br />i <br />15 - <br />20 <br />20 <br />Depth <br />+14 <br />10 <br />1 <br />zir, <br />3 <br />Graphical presentation of the LPI calculation procedure <br />CLiq v. 1.5.1.16 - CFT Liquefaction Assessment Software 54 <br />SL Rvcd 2019.01.21