| Prestressed concrete continuous box girder bridge with reasonable force, structures’ bigstiffness, good driving comfort, attractive shape and easy maintenance etc,is most widelyused in bridge engineering.But, in the construction of this bridge, often because ofconstruction methods, natural disasters and other unforeseen factors led to cracks in themain beam, which seriously affected the usability and durability of the bridge.Therefore,analysis of measures on bridge cracks has great significance.In this paper,a practical bridge in Gansu province which adopts overall constructionwas analysised.This paper uses ANSYS to establish a three-dimensional solid model tostudy the influence of main beam produced by the different thrust, Prestressing steel indifferent locations, Pasting different thickness steel plate and different thickness carbonfiber. The main results are as follows:(1) With the increase of the number of push-point, Maximum tensile stress of the mainbeam is constantly decreasing,and the region of tensile stress is reducing.(2)The thrust of the middle pier has a significant impact on the main beam. With theincreasing of jacking force, the maximum deflection of main girder span value of the piertop and the maximum tensile stress at the value has been reduced.(3) When tensioned a sigle prestressed steel bar, the more tensioned prestressedreinforced floor away from the position of maximum tensile stress and deflection at theposition of the main beam webs more obvious decrease.When tensioned all prestressed steelbars, the effect of strength and stiffness of main beam of the effect produced significantlybetter than taking any position individually tensioned prestressed steel produced.(4) To Paste steel plate and steel carbon fiber always has no effections on the strengthand stiffness of the main beam.(5)When the thrust of the middle pier is250t,and50%prestressing of all prestressingsteel, the strength and stiffness of the bridge are improved. |
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