In this paper the effects of the variation ( uncertainty ) of these two curves on site seismic response are studied . it is necessary to check whether the effects of these on site seismic response are needed to take into account in a real engineering or not 本文分析了这两条曲线值的变化(不确定性)对场地地震反应的影响，及在实际工程中是否需要考虑这种影响，给出了一些定性和定量结果。
