Research And Application Of Key Technique Of Simple Supported Beam Bridge's Asymmetrical Widening

With the development of traffic cause of our country, the traffic of highway bombing everyday, 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 ofcriterion have to be authenticated, repaired, reinforced and redesigned.Generally speaking, if the original bridge can be satisfied widens the standard of loading after reconstructing , they will be kept and reached the widened demand through concatenating new beams at their both sides or one side, because it is more economic to do it in this way . It can also keep the passing through of the vehicle and pedestrian during the process of constructing at the same time. But it has brought the connection question of the new or old structure in the concatenation bridge. The problem which the new or old structure of beam bridges are connected is the research object with the widened highway. Through theory and finite element analytical method widen old bridges change of strength that produce divide among old top structure of bridge because of influencing by newly-built part of the bridge after the concatenation are Analysis and studied, especially Model T beam bridge.After new old main beam splice, original bridge superstructure stress change owing to new part bridge's influence, may result in new and old main beam bridge joint face bearing capacity's insufficiency. in order to guarantee main beam scabbed bridge long-term secure use, I systemly research stress instance of new and old bridge joint face. Because of new and old bridge's type of attachment multiplicity, and new old bridge 'main beam rigidity and spacing also possible of with, result in load lateral distribution subsidence. through theoretical analysis I get the result of original bridge main beam load lateral distribution variance rule and main beam rigidity and spacing factor lead to load lateral distribution change.Additionally, I analyse the influence of joint interface of new and old bridge because of new and old bridge's foundation differ differential settlement. 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 JieFang bridge whole redesign of HeNan province Xing city and introduced the widen widen design of JieFang bridge. It was feasible that JieFang bridge choose mutual independence articulation under the condition of good geology and superstructure rigidity identity. This scheme economy construction cost and short construction cycle by leaps and bound sunder make use of original bridge, get favorable economy and social benefit, provide some experience to design these bridges which need to be broadened in the future.