The Research About The Slip Effect In Outer Pre-stressed Steel-concrete Mixed Continuous Bridge

In recent time the reinforced concrete material at the bridge engineering have been getting widely application however, the friability of concrete material which is fit for pressing but not for tensile, decide a matter of problem that crack in tension always happened in service the value .Adopting prestress technology solves the problem of the concrete crack in tension at the reinforced concrete bearing structure so the prestressed reinforced concrete emerges as the times require. In company with the flying technological development, the construction requires the application of enlarging steel structure and make our best to save the quantity of the steel products usese. The main path to solve this contradictory is keepping on researching and improving on the existing form of steel structure and design theory, also inventing new-style form of steel structure ( including the combination structure and the composite structure ).Besides saving the use of the steel products and dead load, also enlarging the applied scope and inventing unique bridge new-style. During this case, prestress technology is absolutely necessarily, thus the research and application about multiform prestressed composite structure emerge as the times require.The prestress concrete composite beam bridge is a sort of new-style structure developed at the foundation of common composite structure, which is stressing at the steel structrue to the enlarge the elastic range of structure material at the combination of loads and/or prestress action, so that the performance of the high-strength material is given full play. According to the distinctness of the stressing order, it could be divided into pretensioned system and posttensioned amphi- prestress composite beam. Pretensioned system is that stretching prestress steel bundle at the steel beam to form prestress steel beam and then pouring top tray concrete at this steel beam .Post-tensioning method is that stretching prestress steel bundle at the steel beam part of the composite beam after the formation of the steel concrete comp osite beam and at last formming the post-tensioned prestressing steel concrete composite beam.The experimental study and the theoretical analysis proclaims that it is a sort of security, highly active, economy and construction convenient structural shape and is suitable for wide span, heavy load bridge structure。Comparing with the normal concrete,It can reduce investment outlay about 20% more or less.Steel concrete composite beam is a integral structrue whose steel beam and reinforced concrete are jointed by junction piece.It is able to make the most of characteristic of the amphi- material, which has the best technical economy effect, thereby gotten extensive use. In the real work , slipping happened in the interface between the steel and concrete composite beam is inevitable ,which will make the distortion of the composite beam aggrandizement, stiffness degradation and the interface bending resistance bearing capacity decrease. Only considerring the relatively slippage effect in the interface can reflect truelly the real work state of te steel-concrete composite beam.This thesis builted on the foundation of the theses group and the theory of elasticity, principal researched the problem of shorn slip strain in the prestressed steel-concrete combination continuous bridge. At the same time we use finite element program to make a demonstration to this problem, thereinto the second chapter and the third chapter is the textual hardcore.The first chapter is the exordia part. In this part ,we introduce research actuality about the composite beam bridge as well as prestress composite beam bridge,both here and abroad about the research method of the shorn slip strain poor in composite beam and the outcome as well as the textual purpose of research. At present the research about the shorn slip strain poor in the combination simply-supported beam has been relatively maturity, whereas the reporting about the calculate ion of the shorn slip strain poor is nothing. Because most composite beam is the type of continuous beam, Whereas the existence of the shorn slip strain poor musn't be allow neglect, it has significant sense to carring this research.The second chapter is the textual emphases part ,the author adopt the theory of elasticity to push over the interfacial internal force design formula in the combination continuous beam ,also at this foundation ,the author pushed over the shorn slip strain poor design formula of the combination continuous bridge when the concentrated load and evenly distributed load acted.The third chapter is also the textual emphases part. Any theore- tical equation demand that transit proof to illustrate its validity, therefore the author adopted the finite element program to built the composite structure model,to simulate the disposal of the shear key, and we got the shearing force of the interior shear key in corresp- onding cell, according to the shear stiffness formulae of the shear key, we got the value of the shorn slip strain poor of the shear key, which is in reasonable agreement with the velue through the focal of the shorn slip strain poor pulled over in the second chapter. Thereby it is reputed that formulary's validity is true.In the fourth chapter, the aothor made reference to the research of the shear key disposal both here and abroadand and got that the disposal disposal mode of the shear key will make a large influence in the prestressed steel concrete combination continuous bridge.The fifth chapter is the last chapter for the whole-length summarize.This chapter is the summarize about the whole research of the full text and is also a prospect of the further research.