Research On Spatial Stress Characteristics And Crack Analysis Of No.0 Block Of Open Web Continuous Rigid Frame Bridge

For modern urban bridges,people’s requirements are not limited to their basic transportation functions,It has a landscape function and can be coordinated with the history,culture and environment of the city.Obviously,the traditional bridge type can no longer meet people’s pursuit of aesthetics.Since 2013,the first open-web continuous rigid frame bridge in China-Beipajiang Bridge,has appeared.The open-web continuous rigid frame bridge based on the traditional continuous rigid-frame bridge came into being.The zeroth block of the open-web continuous rigid frame bridge is unfolded in space,which is novel and beautiful,and reduces the weight of the bridge and reduces the long-term span.Deflect the problem and enhance the spanning capacity of the bridge.The hollowing of the web at the root of the box girder makes the structure and stress of the zeroth block of the continuous rigid frame bridge relatively complicated.At present,there is a lack of in-depth research on its force transmission mechanism and stress characteristics.This paper takes an open-web continuous rigid frame bridge as the engineering background,the MIDAS and ANSYS finite element software are used to analyze the overall and local structure of the open-web continuous rigid frame bridge.The structural mechanics of the full bridge,the maximum cantilever state of the zeroth block,and the bridge formation state of the zeroth block were analyzed respectively.At the same time,the cracking trend of the zeroth block was studied based on the construction plan.The main research contents of this article are as follows:(1)Aiming at the domestically-built open-web continuous rigid frame bridge,the research status and development trend are expounded,the main stress characteristics of the open-web continuous rigid frame bridge are analyzed,and the cracking status of open-web continuous rigid frame bridge is summarized.(2)Based on Midas/Civil,the finite element model of the full bridge was established,and the overall stress state of the structure was analyzed.At the same time,the crack resistance calculation of the superstructure of the bridge was carried out.The analysis showed that the stress state of the full bridge structure was reasonable and resistant The cracking performance meets the specifications.(3)The finite element analysis software ANSYS and MIDAS/FEA were used to analyze the stress state of the zeroth block,the vertical ten characteristic sections of the zeroth block structure at the maximum cantilever stage were analyzed,and the main The vertical displacement,lateral displacement,longitudinal displacement of the bridge and the stress in the anchorage zone were also analyzed and calculated,as well as the stress of the zeroth block structure in the four most unfavorable condition during the completion of the bridge.The calculation results show that the zeroth block of the bridge is in a reasonable state.(4)Based on the construction technology and materials of the zeroth block,the possible cracking tendency of the zeroth block is studied,and the treatment measures for non-structural cracks and structural cracks are also explained.