本研究之主要目的在於探討影響等量作用週數之因子，最後提出地震規模修正因子(MSF)之初步建議值。等量作用週數乃依據實驗室所得代表性液化權重曲線與強震紀錄而求得，其主要觀念為將地震所造成之不規則反覆剪應力取某一平均應力τave後，依據權重流程轉為等量作用週數Neq。 由於台灣地區地質構造複雜，且地形起伏變化大，因此地震波波形、振幅與延時隨地震規模、波傳路徑、測站所在局部土壤條件及震央距等因素而有所不同，故本研究針對這些影響等量作用週數Neq計算之因素作一系列之探討，以瞭解台灣地區地震規模ML與等量作用週數Neq之統計關係。最後，依據所選用之權重曲線提出地震規模修正因子之初步建議值，結果顯示權重曲線之斜率對於MSF之評估結果影響甚大。 In this research, we study the influence factors on the equivalent number of uniform stress cycles Neq and propose magnitude scaling factors for liquefaction analysis. Based on the cyclic strength weighting curve and acceleration history, the equivalent number of uniform stress cycles were determined by a standard weighting procedure. The weighting procedure can convert an irregular time history of earthquake-induced cyclic stresses to a series of uniform cycles with average shear stress τave. The geological structure and terrain is complex in Taiwan, therefore, we study the influence factors on the equivalent number of uniform stress cycles, which include the waveform(amplitude and duration of acceleration history), magnitude, the path of wave propagation, site condition and epicentral distance. When the relationship of earthquake magnitude and equivalent number of uniform stress cycles was established, the magnitude scaling factor for liquefaction analysis were derived from the weighting curve. The results show that the slope of weighting curve is the important factor for influencing the magnitude scaling factor.
