[提要]  通过10个算例，对按振型分解反应谱法和弹性时程分析法所得的底层地震剪力值与按底部剪力法所得的值进行对比和分析，而后从统计意义上提出了随第二层与第一层侧移刚度比值而变化的底层地震剪力增大系数计算公式。
[关键词]  底框砖房 底层地震剪力  增大系数 底部剪力法 弹性时程分析法

Ten examples of the masonry buildings with R.C. framework bottom floor were calculated and analysed by the following three methods respectively, bottom shear force method, response specirum technique and elastic step by step integration. The bottom floor seismlc shear forces obtained by the three methocls were compared, and then the calculating formula for the amplifying coefficient of the bottom fkx)r seismic shear force was proposed.
Keywords: masonry building; R.C. framework; bottom floor, amplifying coefficient; seismic shear force; bottom shear force method