The Research About Some Questions Of The Old Bridges' Being Entirely Broadened

With the development of traffic cause of our country, the traffic of highway bombing everday, some highway have to be redesigned because they can not meet needs. When the highway need to be broadened, We must redesign the bridges and the culverts. When we redesign these bridges which can not meet needs, load-bearing capacity questions come up with them. So, I want to study some of them and hope that I can bring some help to some engineers of bridges.We deal with these bridges which can not meet the needs of criterion, Compare to technique and economics, We add these bridges'width on the basis of new standards in order to make full use of original bridges. The bridges which can not meet the needs of criterion have to be authenticated, repaired, reinforced and redesigned.The paper thoroughly analyses stipulation condition of old bridges'whole redesign, makes use of the theory on shrinkage , cheep, and foundation subside changes, carries on relevant project comparison, choose and systematical analysis, deals with the longitudinal sew's shearing deformation between the new and old bridges, chooses proper conjuction craft and method , solves the questions of the old bridges' being entirely broadened , makes the new and old bridges work harmoniously, in order to meet traffic need. I verify them with T beam bridge whole redesign of Foshan-Kaiping superhighway and provide some experience to design these bridges which need to be broadened in the future.