-Q&A Q.Let me know how to calibrate liquefaction parameters through soil element simulation. What status of element simulation is judged as the satisfactory condition to determine the liquefaction parameters?

- and or
- All categories
- Admission
- Purchase
- FLIP programs
- Analysis
- Others

Let me know how to calibrate liquefaction parameters through soil element simulation. What status of element simulation is judged as the satisfactory condition to determine the liquefaction parameters?

Ideally, when the results of undrained cyclic triaxial shear test measured in the laboratory is exactly matched with those computed at double amplitude of axial strain difference of 1 ％、２％、５％、and 10％ in terms of liquefaction resistance curves, then element simulation status is judged satisfactory to finalize the calibration of liquefaction parameters.

These double amplitude strains of axial strain difference in triaxial test are equivalent to a single amplitude of shear strain of 0.75％, 1.5％, 3.75％, and 7.5％.

Soil element simulation in FLIP is generally judged in terms of single amplitude of shear strain.

A certain degree of tolerance may often have to allowed in the degree of fit between the laboratory test results of liquefaction and results of simulation in practice.
In this case, an engineering judgement is required such as to ignore an abnormal point of test results, to put high priority in the results at higher stress ratios because input earthquake motion is intense, or inversely, to put high priority in the results a lower stress ratios with large number of cycles because input earthquake motion is moderate or weak but with a large number of cycles.