Pile soil interaction

The error message tells that some command lines(for pile definition) in PSI file were in wrong format which were not recognized by SACS. You may attach your psi file or give a screen shot here so that we can found the reason.

Thanks for reminding got it

Improper soil properties may cause this problem when perform non-linear pile-soil interaction analysis, please verify your soil input with soil report.  

Can  we use different yield strengths for piles and legs

Normally increasing the stiffness of soil could solve this problem and the question in your file comes from P-Y curve. I tried to reduce number of soil stratum to 6 instead of 47(soil data from top 6 stratums) and it works with no error 

If i have pile penetration length of 50  meters 

What I do is to make 6 stratums lines at depth 0，10， 20，30， 40， 50 for P-Y curve, and just use soil properties of top 6 stratums in your current PSI file(Ignore other 40 depths). In this case the analysis can be performed without error which tells us the current soil properties has improper stiffness for this structure. So you need to check py curve of each soil stratum.

What I do is to make 6 stratums lines at depth 0，10， 20，30， 40， 50 for P-Y curve, and just use soil properties of top 6 stratums in your current PSI file(Ignore other 40 depths). In this case the analysis can be performed without error which tells us the current soil properties has improper stiffness for this structure. So you need to check py curve of each soil stratum.