Abstract:The influence of support settlement on the seismic impact analysis of long-span steel structure corridors is often overlooked, but is very important. In this paper, such an influence was studied, and a stress model of the long-span steel structure in earthquakes was established. Incorporating settlement amount into the model, the additional internal force of the corridor (including steel frame and steel truss) under earthquake impact was calculated. The additional bending moment diagram of the corridor was then drawn using structural mechanics, and the seismic impact expression of the settlement on the steel frame of the connecting corridor was obtained. The internal force change of the steel truss structure connected with the corridor under different settlement levels was analyzed with SAP2000 software. The maximum bending moment and maximum axial tension of the upper and bottom chords on the corridor were then calculated under earthquake conditions. The experimental results showed that after support settlement, the maximum dynamic coefficients of the upper chord and web member were 0.17 and 0.15, respectively, which was closer to the relative code value (0.16) than the results achieved through the traditional time-history analysis method.