sensitive analysis and arc length control in Plaxis 2D

Hi all and

1. Can anyone explain about how we can use sensitive analysis to get the required parameters?

2. In arc length control, how the arc is defined?

Thanks.

  • Above with that above, why senstive analysis only shows criterion 1 (provided safety analysis in criterion 2) and sensiScore based on what criterion?

    after doing parameteric analysis how to find which is worst what is meant by mini and max?

    Thanks

  • Hi,

    Sensitivity analysis is not really my expertise, but simply reading the Reference Manual I pretty much find the answers to all your questions. Well, apart from your question why it the table says "Criterion 1".... I think that is a mistake, it should be "Criterion 2" because the values seem typical SumMsf values to me, which is Criterion 2.  The SensiScore is then based on the SumMsf criterion.

    With respect to the 2 buttons, they're to show the Min- and Max projects of the sensitivity analysis and the list below are all the projects with their parameter variations that have been calculated.  There is no worst or best for a computer, only for humans. A computer only knows a minimum value and a maximum value....whether that is good or bad is up to the engineer. The Min project contains all the minimum values results of all parameter variations and the Max project all the maximum values. Note that those minimum and maximum values come from different parameter combinations: hence in the Min project the minimum displacement for node X may come from a different parameter combination than the minimum displacement for node Y, and the minimum multiplier SumMsf from maybe even another parameter combination. See paragraph 11.3 from the PLAXIS 2D V21 Reference Manual.

    With kind regards,

    Dennis Waterman

  • Noted with thanks 

    Please tell the answer for this , thanks

    In arc length control, how the arc is defined?

    I have 2 more question here as the max and min results from the parametric analysis provided the max and min results in the analysis based on the parameters which will be in a different combinations. My questions are 

    1. If we provided 2 criterions lets say the vertical displacement on one node and FOS (strength reduction factor), here which value is considered as max and min as both may not coincide? 

    2. In one analysis i provided 2 criterion as shown below.

    and did parameter variation analysis as shown below.

    when i see the failure case the failure line extended from 1 to 2nd layers of the soil 

    when i checked the FOS for the max and min output from the parametric analysis results the values are shown below

    but when i checked the soil parameters of the two layers in the two analysis the same values as shown below.

    Layer 01 (not include in the par analysis but i showed here), (order max and min)

    Layer 02 (order max and min)

    Why is like that?