Study on high speed railway prestressed continuous rigid frame bridges

摘要

For high-speed railway prestressed concrete bridge, to control the deflection of the bridge as thernstandard, studying the key technologies of the bridge design and construction, finite element methods to calculaternand analyze the Static characteristics of the beam bridge. The design of the main consideration load as: weight,rntemperature gradient, the settlement of bearing, the second phase load bearing (uniformly distributed load),rnmoving load on the influence of the bridge deflection in the same bridge design provides technical reference.rnThe construction monitoring procedure of the five-span continuous rigid frame bridge (80m+3×145m+80 m)rnofWenzhou-Fuzhou high-speed railway, the way of construction monitoring, simulation calculation, calculationrnof elevation, and measurements of elevation and stress are introduced in this paper, and controlling situationrnof alignment and stress of the bridge is emphatically analyzed. Also, comparative analysis on the influencernof changes of bulk density and elastic modulus of concrete on the final bridge line is made, which comes arnconclusion that the change of bulk density of concrete is more effective. So field test of influence parameters ofrnthe final bridge line is recommended besides the calculation analysis to reduce the difference between theoreticalrnelevation and actual elevation. Finally, this paper concludes the situation of calculation analysis and constructionrnmonitoring: formwork erected with relative elevation method can remove temporary load’s effect and effectsrnof stochastic factors and can get a smooth final bridge line; a better theoretical elevation can be calculated ifrnparameters are corrected according to field tests. The controlling measures such as adjusting the Elevation andrnControl weight are taken for the construction, in accordance with the results of the analysis in order to ensurernthat the stresses and alignments of the beam can meet the relevant code requirements at each construction stagernand the bridge is completed successfully. The reference information is provided to the another bridge.