Research On Mechanics Behavior And Key Technology Of Design For Urban Wide Box Girder Bridge

Prestressed concrete continuous box girder bridges with its structural properties having a transverse,torsional stiffness,deformation is small,smooth linear,driving comfort,simple construction process,reasonable economic indicators,etc.,in the country has been widely used and promoted.Currently,large-span beam bridge cantilever length generally adopted a wide cross section of the box,to reduce weight and to facilitate construction.Current bridge design,the general use truss beam element calculation and analysis,there is no spatial simulation,resulting in concrete box girder crack problems in the construction and operation of the process.In this paper,based on Bridge Of XiangYang River project,the method of establishing the refinement of finite element analysis model,focusing on research and analysis and design of key technologies girder bridge wide mechanical behavior,including the following aspects:1.Study on Wide Box Girder Bridge in different roles(load)under(dead loads,live loads,temperature changes,prestress)of space the forces and internal forces lateral transfer mechanism,the study found that a large box girder near the top and bottom webs region undertaken moment percentages,measures should be taken in the bridge design process is necessary to strengthen the region,in particular bear a greater moment control section.2.Study on Wide Box Girder Bridge in different roles(load)under(dead loads,live loads,temperature changes,prestress)shear lag effect,the results showed that: Bridge Of Xiangyang River's Wide Box shear lag effect is more significant,and fulcrum sectional exceeds the device specifications more.3.To carry out a different way of prestressed Sorbian Wide Box and deformation and stress of the box girder structure and stress state of the research agreement,including the following three aspects: the vertical arrangement of prestressed impact studies,longitudinal prestressing Effects of the arrangement,prestressed tensioning sequence,the results showed: vertical prestressed can effectively reduce the size of the internal web principal tensile stress,but shorter vertical prestressing steel,tensioning process prestressed greater losses,recommended secondary tensioning process.Vertical prestressing construction,we recommend a hysteresis segments tensioned vertical steel beams.4.To carry out stress analysis of the number 0 block,it concluded: 0 extraordinary hole chamfered end of the block the emergence of local stress concentration,principal tensile stress beyond the tensile strength of concrete,so in that position should be configured enough to crack ribs,but also should try to structure the turning point and the chamfer made smoother smooth,avoid sharp corners appear to ease the stress concentration phenomenon.5.Research undertaken to rationalize the structure in the form of wide box girder structure and form of reinforcement.