Finite Element Analysis Of Key Mechanical Problems Of Continuous Rigid Frame Bridge During Construction

Taking a three-span girder for example, the author introduces the traits of pre-stress concrete continuous rigid frame bridge, and the methods and characteristic of the construction stage. The stress intensity and deformation of pre-stress concrete bridge are important performance indicators in safety evaluation. On the basis of the theory of structure design, numerical analysis of the cantilever casting stage and consequently in-depth research on following two aspects of problems are carried out.1.Dimensional intensity is an important performance indicator of the bridge in safety assessment. Using the generic finite element program ANSYS, the displacements and stresses of the zero block are simulated. The computed results show the performance and stress distribution in this area in different load cases, then suggestions for preventing girder from crack and reinforcement are furnished.2.Considering the importance of precamber design and deformation monitoring during construction, the deflections of this bridge during cantilever casting construction are obtained by 3-D finite element analysis. The computed deflections are compared with the theoretical values in consideration of the variable cross-section and the ones obtained by on-site monitoring. On the basis of qualitative analysis on several important factors impacting on the deflection during construction, the comprehensive modifier in assessment formula is quantitatively analyzed through the comparison of three sets of data, thus the basis of precamber design instructed by the numerical analysis is furnished.3.A systematized way of analyzing the intensity and deformation of bridges in this type with ANSYS is concluded:such as the finite element model building, construction simulation by element birth and death function, model solution and the analyses of results. On conclusion, the in-service condition of this bridge during construction is in security.The results of the finite element analysis in this thesis reasonably expound the mechanical behavior of the construction process of the bridge, which provides the referential value for the design and construction of the same type of bridges.