# Post liquefaction residual strength

**URL:** <https://forum.itascainternational.com/t/post-liquefaction-residual-strength/2214>\
**Category:** FLAC\
**Tags:** flac2d\
**Created:** [August 27, 2025, 6:33pm UTC](https://forum.itascainternational.com/t/post-liquefaction-residual-strength/2214 "2025-08-27T18:33:13Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Milads](https://avatars.discourse-cdn.com/v4/letter/m/ecccb3/32.png) [@Milads](https://forum.itascainternational.com/u/Milads)\
**Post date:** [August 27, 2025, 6:33pm UTC](https://forum.itascainternational.com/t/post-liquefaction-residual-strength/2214/1 "2025-08-27T18:33:13Z")

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I am running a 1D seismic site response analysis with FLAC 2D v8.1 and would like to know whether it is possible to extract the post-liquefaction residual strength directly from the model. I am using the PM4Sand and PM4Silt constitutive models.

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**Author:** ![jwang](https://avatars.discourse-cdn.com/v4/letter/j/b782af/32.png) [@jwang](https://forum.itascainternational.com/u/jwang)\
**Post date:** [August 28, 2025, 2:33pm UTC](https://forum.itascainternational.com/t/post-liquefaction-residual-strength/2214/2 "2025-08-28T14:33:20Z")

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Is the residual strength already saved in the model (fish/model property) and you like to extract the data from the model and save as a txt file?

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**Author:** ![Milads](https://avatars.discourse-cdn.com/v4/letter/m/ecccb3/32.png) [@Milads](https://forum.itascainternational.com/u/Milads)\
**Post date:** [August 28, 2025, 5:13pm UTC](https://forum.itascainternational.com/t/post-liquefaction-residual-strength/2214/3 "2025-08-28T17:13:38Z")

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No, I am not currently tracking that in a FISH code. Could you provide an example FISH script to track the post-liquefaction residual strength in PM4Sand or PM4Silt?