Stress Analysis In The Negative Moment Of Prestressed Concrete Simple Supported-continuous T-beam Bridge

Prestressed concrete simply supported continuous bridge in the small simply supported span bridge type is irreplaceable bridge. This bridge has several features, including the construction convenient, excellent mechanical properties, comfortable when driving. In simple supported-continuous bridge, precast main beams when building bridges are simply supported state, after pouring wet joint structure becomes continuous beam is statically indeterminate state. For simply supported-continuous bridge is generally on the overall structure of the force analysis. The negative moment area structure is an important part of Simply Supported-Continuous bridge force change, it is necessary to carry out detailed calculations and analysis.This thesis relies on Baby River Bridge project. During the construction of the bridge, the bridge has been stress-strain tests. The continuous three-span simply supported T beam bridge overall structural model was built using Midas/Civil software. The model is established and analyzed, according to the actual situation, in terms of constraints, loads, construction steps and so on. To more clearly reflect the mechanical characteristics of the negative moment area, based on the overall structure of the model, using Midas/FEA model to establish a local entity negative moment area, analyze the forces negative moment area. The data of the section is analyzed, in order to determine whetlier the correct of model. In the overall model, analysis of the structure of the whole mechanical characteristics. In the partial model, analyzing the specific trends negative moment area.By analyzing the pier top section of cast concrete with different loading time is affected by the force of the span and the negative moment area, and comparing the change in the centre beam and side beams, side span and mid-span internal forces of different effects, drawing various sections after serving as a bridge in the time variation of the bending moment of the increase. At the same time, the influence of long term creep on the structure is discussed. By studying the impact of the structure from the negative bending zone of prestressed steel beam position and length, analyzing the influence of distance between negative moment steel beams and roof on the internal forces control section, and discusses the changes in the length of negative moment tendons on the bending moment control section, providing reference for the selection of a reasonable distance between negative moment steel beams and roof and length of negative moment tendons. By studying the impact of the width of the pier top section of the cast of the negative moment area, analyzing the stress effects on different beams of the width of the pier top section of the cast, and focuses on the forces of negative moment area, obtained pier top diaphragm beam width to facilitate the construction, without affecting the force.