Analysis Of Parametric Sensitivity For Long Span T-type Rigid Bridge Constructed With Rotation Method

In the modern times, great progress and development has been made in thebridge construction in our country. Thus, it is confronted with building a large numberof bridges to overpass the obstacle (a railway or a highway) or other specialconditions along with the unceasing improvement and expansion of road network. Inorder to reduce the impact on the existing traffic, rotation construction of bridge iswidely used in China. The method not only has minimal impact on marine traffic, butalso can ensure the crossing safety and economic applicability. With the purpose ofoptimizing the design and construction of the bridge structures constructed byrotation method, it is necessary to lucubrate and dissect the design parameters of therotation bridge. The essay analyses the sensitivity of the rotation bridge according toparameter sensitivity analysis theory, thus improving quality level of the similarbridges. The main content of this article are as follows:(1)This thesis discusses the characteristics of the bridge design and constructionfor the swivel bridges. Then the parameters of the bridge on design and constructionare definite. Therefore, the research meanings are put forward and the researchsituation on analysis of parametric sensitivity for long span T-type rigid bridgeconstructed with rotation construction are elaborated.(2)The paper introduces the principal theory and research method of parametersensitivity analysis in theoretically. On the rotation bridge structures, the structuralparameters of bridge are put forward that may affect the behavior of bridge structure.In addition, the single factor and multi-factor method are carried out to identify themain sensitive factors. As a result, the main impact factors to bridge stress andalignment will be counted.(3)The numerical model is set up of T-type rigid frame bridge by rotation basedon the model modification. Combining the on-site construction process monitoringwith on-line measured data in Inner Mongolia, the author utilizes the finite elementsoftware (MIDAS CIVIL2012&DR BRIDGE3.3) to simulate practical stress anddeformation situations of the T-shape rigid bridge. By updating and consummatingthe finite element models of structures, the models could meet the practical situation. (4) According to the calculations the main factors that may affect the structuralbehavior of bridge are found, including material parameters such as girder concrete,prestressed reinforcement, cross-section characteristic, bridge deck pavement and soon; as well as operational factors such as vehicle load, temperature action, shrinkageand creep of concrete, foundation uneven subsidence and so on. By controlling thoseparameters within a certain range, structural response of the finishing stage isassessed. Compared with the structural response, the relative change and absolutechange of each concrete structural response are obtained consequentially, during thevarying procedure of the parameters. Finally, the analysis results are collected,generating the order of sensitivity according to each specific structural response,which is used for adjusting displacement and internal force in time during theconstruction. The modulus of elasticity is not sensible, but the density and externalprestressing are the sensible factors.(5)Different from the single factor analysis, multi-factor analysis is a one-by-onecombination of material parameters and operational factors. Similar to the singlefactor analysis, multi-factor analysis discusses the sensitivity to the stress andline-shape through varying the model parameters. Last but not the least, it can ensuresafety of structures in construction and to guarantee the line shape and stresssituations of the bridge after construction to meet relevant design criteria. The resultsshowed the tendency of the stress is the same as the single factor analysis, that is tosay, the larger outside force, the lower the stress and the compressed stress will bereduced. Also the tensile stress maybe appeared. The density, external prestressing,live load and support settlement are also the sensible factors.The conclusions of this paper can be useful for the design and construction andoperation departments of the similar bridges.