Large Span Frame Bridge Jacking Construction Space Finite Element Analysis

With the rapid development of China’s city construction, railway speed increase and road traffic safety requirements, the cross problem of existing railway and highway crossing has become more and more outstanding, there is an urgent need to change this situation. In view of the coordination of city traffic environment、reduce the construction cost and other factors, the range of application of the frame structure underpass bridge is becoming more and more widely. Jacking construction technology is the most commonly used technology in the frame structure underpass bridge construction, however, the force situation is more complicated in the jacking construction process, and affected by various factors.So the space finite element analysis is particularly important.It has a good reference significance to built or under construction engineering, especially to the large span, asymmetry, oblique underpass bridge.This paper takes the three-span, asymmetric, large oblique and large span frame underpass bridge as the research object. Using the MIDAS CIVIL finite element analysis software, based on the thick plate finite element theory, it uses the board unit, and gives full consideration to the actual loads in the structure force analysis. Under the overall warming and overall cooling conditions, the change of stress and strain and internal forces can be analyzed, and the structure stress variation rules can be summarized.This paper can provide reference for the prevention and control of the engineering cracks.