The results of probabilistic seismic hazard analysis for actual project show that

magnitude integral step and seismic hazard curve control points can lead to significant differences in the calculation results

even if whole input parameters are identical

including potential source and attenuation law.For the seismic hazard analysis software that accumulates sub potential source area dxdy according to the attenuation law

magnitude integral step is suggested to be less than0.05.The range of hazard curve control points should be large enough

the control points should properly increase density with logarithmically uniform values

in order to ensure relative accuracy of response spectra of different periods for different probabilities of exceedance

which are distributed across several orders of magnitude.Above selection of integral step and control points is subjective uncertainty that appears widely in engineering problems with numerical calculation.The influence can be reduced or even eliminated by reducing the integral step

and increasing control point density.Sensitivity of the effects of such uncertainties is related to the skills of software programming.For specific software

reasonable values

taking both computational speed and accuracy into account

are not difficult to determine by changing the integral step and control point density and comparing the trial results.