关键词: 连续箱梁桥：内力增大系数：等代简支跨, 双弹簧支承计算模型, 修正偏心压力法．

Abstract: To calculate the increasing coefficient of internal forces for continuous box girder bridges the calculating model with two spring bearings is established．The analytical results of an example by this model coincided satisfactory with those by the traditional method,and it simplified the calculation process to a certain extent with the latter．

Key words: continuous box girder bridge, increasing coeficient of internal force, equivalent span of simple supported beam , calculating model with two spring bearings, modified excentral pressure method