The first message is just a warning indicating that the methods used to generate the P-Y or T_Z curves falls outside of the validity range and the CPT method is recommended instead. This will not cause the analysis to fail.

The second error indicates that there is instability at the pile tip. I see a ‘Y’ option on the SOIL LATERAL HEAD line which I believe will modify the stiffness at the pile tip. I can’t say for sure because I can’t see exactly what column it’s in. Try changing that option to ‘N’ and see if you get the solution to converge.

Regards,

Geoff 

Thanks Geoff

Done that & still get the same warning and error re singularity. My main issue was why the example/sample problem two in SACS manual does not even run with the SPI SACS program. I had a different problem that I was solving using PSI. I kept getting errors which did not make sense and just to test PSI I run the sample problem hoping I can run that & then modify the file to run my problem. I both cases the program keep giving me errors.

PLOPT ENUC                                                                                                             
PLTRQ SD                                                                                                               
PLGRUP                                                                                                                 
PLGRUP PL1           28.0  1.00              50.0    50.0                                                              
PLGRUP PL1           28.0  0.75              36.0   175.0                                                              
PILE                                                                                                                   
PILE     2 201 PL1         1.0       1.0       8.0                  SOL1                                               
SOIL                                                         ICP                                                       
SOIL AXIAL   HEAD  8                    SOL1                 ICP                                                       
SOIL API AXL SLOC  0.001  20.0 SILT   1.0        50.0                                                                  
SOIL API AXL SLOC  20.00 60.00 SNSL   1.0       100.0                                                                  
SOIL API AXL SLOC        160.0 SLSN   1.0        40.0                                                                  
SOIL API AXL SLOC        200.0 SAND   0.9        80.0                                                                  
SOIL API AXL SLOC        228.0 CLOC  20.0        50.0                                                                  
SOIL API AXL SLOC        260.0 CLUC  40.0        70.0                                                                  
SOIL API AXL SLOC        300.0 CLAY  70.0        90.0                                                                  
SOIL API AXL SLOC        400.0 ROCK 100.0 200.0 100.0                                                                  
SOIL TORSION HEAD                 1000.0SOL1                                                                           
SOIL LATERAL HEAD  6          28.       SOL1                                                                           
SOIL API LAT SLOC SILTSA         20.     0.5        50.0  20.0                                                         
SOIL API LAT SLOC SNSLCA  20.0           1.0        60.0  60.0                                                         
SOIL API LAT SLOC SLSNSA  60.0           1.5        70.0 125.0                                                         
SOIL API LAT SLOC SANDSA 120.0 140.0    1.75        80.0 125.0                                                         
SOIL API LAT SLOC SANDSA 140.0          2.00        80.0 125.0                                                         
SOIL API LAT SLOC CLAYS  200.0          3.00       100.0 0.250 0.001                                                   
PLSTUB   D1002      2.2802    0.01306   625.4                                                                          
END                                                                                                                    
                                           

My original problem was a simple pile but I keep getting error in line 4 re format but do not know what is wrong

PSIOPT   METC Y       EX                                  S3                                                           
PLTRQ SD                                                                                                               
PLGRUP                                                                                                                 
PLGRUP PL1          40.64   1.0              27.5     36.                                                              
SOIL                                                                                                                   
SOIL AXIAL   HEAD  2     2.039          SOL1                 ICP                                                       
SOIL API AXL SLOC    8.0  20.0 SAND   1.O                                                                              
SOIL API AXL SLOC  20.00   36. CLAY   70.0       2.36                                                                  
PLSTUB   FD1002     10.0                100.0                                                                          
END