Note on Liquefaction Analysis

General

When performing a liquefaction analysis, you must use the appropriate correction factors for the specific analysis method (as outlined in the reference articles), otherwise, you will be violating the assumptions of the published works.

Please see the Liquefaction references for more information.

K Alpha

Alpha is defined as the ratio of the initial static shear stress to effective vertical stress by Seed (1983). In Settle3, Kalpha is approximated as the tangent of the slope angle, and the variation with depth is neglected in this simplification.

Note on Settlement and Lateral Displacement

The following assumptions are made with regards to the calculation of settlement and lateral displacement:

1. Settlement calculations only extend as far up as the last specified data point. If you want the topsoil layer to be included in settlement or lateral displacement calculations, a liquefaction data point must be present in that layer.
2. In a multi-layer model, you can have at most one layer without any liquefaction data point between any two consecutive data points of the input table. That mid-layer can be prone or not prone to liquefaction.
3. Liquefaction analysis only allows users to enter data as depth below ground surface. If the project setting is set as elevation mode, the soil profile color will not appear on the graph and the results may not be consistent as the model is showing elevation mode while the inputs are in depth. For consistency of the results and visualization, we strongly encourage users to keep the same setting by selecting: Home > Project Settings > Soil Profiles and select 'Depth below Ground Surface' under the vertical axis setting.