Study On The Structure Condition Of Prestressed Concrete Box Girder Bridge Before And After Strength

The prestressing concrete box girder bridge has a lot of advantages, which includes few bridge surface joint seams, small beams, strong stiffness, spectacular outside design and easy maintenance characteristic etc. Since 1970s, China has built a lot of concrete box girder bridges. However, due to the design limitation, low load standard & limited infrastructures at that time, many problems occured after the bridges started their normal business, all of these problems brought very bad influence on the bridges affordability especially after long-terms heavy loading & high volume transportation. These problems are listed as below.Unreasonable calculated cross section size for box beam bridges during the general main body design for the whole prestressed concrete box girder bridge, lower curve & shear capability due to lack of consideration of temperature factors, underestimation on the sub-incentre for the statically indeterminate prestressing concrete box girder design. Mainly put emphasis on analysis & study together with actual examples for the appeared problems, recent bridge quality investigation& strength techniques study, and study on bridge conditions after its strength! Our serious study and analysis for the actual projects, together with scientific test for the present seam quality, reasonable strength & improvement to restore bridge load ability, which is significant for eliminating hidden traffic accidents, improving transit volume & transportation services!...