Calculation Study Of Seismic Performance Of Skew Bridge

In the highway system, irregular bridge, e.g. skew bridge, is frequently adopted formid-span bridges and small span bridges for its geometry adaptability, but its seismicdesign is more difficult than that of regular bridge because of its geometry irregularity.The study shows that skew bridge was destroyed by the earthquake more seriously withunique characteristics than linear bridge according to destructive earthquakes in the past.Presently, the research on seismic response computation theory and seismic responsecharacteristics of skew bridge is limited and incomplete. So in this paper, skew girderbridge with single span is the research object, and seismic response characteristics aremainly discussed.Based on earthquake damage investigation of some skew bridges in “5.12”Wenchuan earthquake and some overseas earthquakes, earthquake damage features,occurrence mechanism and influence factors of skew bridges are analyzed andsummarized in this paper. In addition, rules about the seismic design of skew bridges indomestic and overseas specifications are briefly introduced, and announcements ofseismic design for skew bridges and questions needed to be further studied are alsopresented in this paper. Seismic response analysis is conducted for simply supportedskew girder bridges with single span through Sap2000finite element program. Seismicresponse features of skew girder bridges where collision effects of expansion joints andblocks are included are mainly analyzed and concluded. Achievements of this paper arelisted as follows:①The slab rotation of single span skew bridge which without collision effects areanalyzed and concluded, where nonlinear history for variable angle input seismic waveis mainly analyzed.②Single span skew bridge with collision effects of expansion joints included iscalculated and analyzed, where nonlinear history for variable angle input seismic waveis mainly analyzed, and sensitivity analysis is also done for factors which affectmaximum rotation angle and residual rotation angle of the skew bridge deck.③The collision effects of expansion joints and blocks are simultaneouslyincluded. The seismic response characteristics of single span skew bridge are analyzedand concluded. Sensitivity analysis is done for obliquity, initial gap of blocks, collisionstiffness of blocks and seismic wave with different amplitudes which affect maximum rotation angle and residual rotation angle of the skew bridge deck.