Liquefaction Options - CPT

The following additional correction factors can be applied when performing a liquefaction analysis with CPT data:

Magnitude Scaling Factor (MSF)

The Magnitude Scaling Factor is used to adjust the CSR or CRR to an earthquake magnitude value of M=7.5.

The following options are available for MSF:

• None
• Tokimatsu and Seed (1987)
• Idriss (1999)
• Andrus Stokoe (1997)
• Idriss and Boulanger (2008)
• Idriss (NCEER)
• Idriss and Boulanger (2014)

Stress Reduction Factor (Rd)

R_d is the shear stress reduction coefficient, and is used to determine the maximum shear stress at different depths. Typically, values range from 1 at the ground surface to lower values at greater depths.

The following calculation methods are available for R_d:

• NCEER (1997)
• Idriss (1999)
• Kayen (1992)
• Cetin et al. (2004)
• Liao and Whitman (1986)