Target Displacement Calculation

[emreakin]

I have been trying to find the target displacement by comparing the pushover capacity curve with the demand spectrum according to the Turkish Earthquake Code. The program automatically calculates the target displacement as 0.17 m. (for a DD1 level ground motion-2% prob. of exceedance in 50 years). However, I found this value as 0.09 m when I try to do it manually by drawing the demand spectrum and capacity curve in spectral coordinates..one on each other. I checked it several times but the difference is valid. I enter the soil type etc correctly in both cases. What may be the reason of this? Is it possible that Seismostruct doing something wrong? Or am I? What is the methodology that Seismosoft applies to find target displacement?

[emreakin]

I found my error while calculating the elastic demand spectrum in excel. Still, I will be happy if you please give a reply about how the target displacement is determined according to Turkish Earthquake Code by Seismostruct. Which method is applied to determine the target displacement? Does the software apply the same rules given in Part 5B (the iterative procedure) of Turkish Earthquake Code?

[seismosoft]

Indeed the target displacement is calculated employing the procedures of TBDY. The iterative procedure is employed but only for a single corrective iteration, since we have found out that a large number of iterations often leads to unrealistic target displacements.
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