Optimistic Study On Longitudinal Seismic Construction Measure For Railway Transit Girder Bridges

Earthquake has become one of the most serious threatens to human beings for its increasing frequency lately. The fact of bridge seismic damage indicates that the deficiency and undermining of principle of structure is a key factor to cause seismic serious damage. Construction measure is the practical result that contains earthquake disaster, theoretical analysis, and numerical calculation. This paper researches the railway transit girder bridge influenced by violent earthquake from two aspects: unseating prevention device (UPD) and restrainer, and then supplies rational parameter value.Longitudinal (UPD) is an effective measure in collapse prevention systems for railway transit girder bridge. If there comes an earthquake which goes beyond the anticipate seismic fortification intensity, the strong shock will destroy the bearing or the restrainer, and oversize relatively displacement will likely to be created between the superstructure and substructure. According to the rational UPD, it can guarantee the displacement between pier and girder won't go so far as to exceed the bearing length of the beam head. The problem of structural collision is another key factor to affect the structure seismic response and earthquake-resistant behavior under an earthquake. Using a rational rubber block and seismic restraint stop can decrease the percussive force and control the bridge response effectively, so they will have better effect in the construction. The main works and result are listed as follows:Firstly, a representative finite element analysis model of railway transit girder bridge is established by SAP2000. The methods of nonlinear dynamic time history analysis is applied respectively, in order to study the influence of the seismic response at different seismic wave in different PGA, and suggest the different value of the UPD's stiffness.Secondly, a model of single track of two-span railway transit simply-supported girder bridge is established, and optimal methods of anti-collision device is also discussed, which is based on the analysis on the influences of girder bridge responses for earthquakes caused by stiffness of anti-seismic stops and the changes of expansion joint lengths in the thesis.Thirdly, the method of Pushover is applied for UPD anti-seismic performance checking to illustrates that UPD setting has a positive influence on the structure. Use capacity spectrum curves to analyze the elastoplasticity response of the structures, which can help us to take further proving of the UPD's function...