SEISMIC RESPONSE COEFF. CALC HELP

[ctmfab]

For vertical pressure vessel, or "Nonbuilding Structures", IBC 2000 applies the rules of 1617.4 to determine the seismic base shear (for non-rigid structure). I was checking the output of a vessel program and it did not include a calculation for the upper limit for Cs as defined by Eq 16-38. The only calcs were for Cs per 16-35 and the lower limit at 16-75.

Is this upper limit typically disregarded for nonbuilding structures, or is there an error in the calculation? It would make a significant difference in the calculation at hand.

Here is some of the info for the design:
Site Class D
T=0.77sec
Ss=1.0
S1=0.4
R=3

Thanks